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cmd/devp2p, p2p: dial using node iterator, discovery crawler (#20132)

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* p2p/enode: add Iterator and associated utilities

* p2p/discover: add RandomNodes iterator

* p2p: dial using iterator

* cmd/devp2p: add discv4 crawler

* cmd/devp2p: WIP nodeset filter

* cmd/devp2p: fixup lesFilter

* core/forkid: add NewStaticFilter

* cmd/devp2p: make -eth-network filter actually work

* cmd/devp2p: improve crawl timestamp handling

* cmd/devp2p: fix typo

* p2p/enode: fix comment typos

* p2p/discover: fix comment typos

* p2p/discover: rename lookup.next to 'advance'

* p2p: lower discovery mixer timeout

* p2p/enode: implement dynamic FairMix timeouts

* cmd/devp2p: add ropsten support in -eth-network filter

* cmd/devp2p: tweak crawler log message
This commit is contained in:
Felix Lange 2019-10-29 16:08:57 +01:00 committed by Péter Szilágyi
parent b0b277525c
commit 2c37142d2f
19 changed files with 1559 additions and 414 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

152
cmd/devp2p/crawl.go Normal file
View File

@ -0,0 +1,152 @@
// Copyright 2019 The go-ethereum Authors
// This file is part of go-ethereum.
//
// go-ethereum is free software: you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
//
// go-ethereum 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 General Public License for more details.
//
// You should have received a copy of the GNU General Public License
// along with go-ethereum. If not, see <http://www.gnu.org/licenses/>.
package main
import (
"time"
"github.com/ethereum/go-ethereum/log"
"github.com/ethereum/go-ethereum/p2p/discover"
"github.com/ethereum/go-ethereum/p2p/enode"
)
type crawler struct {
input nodeSet
output nodeSet
disc *discover.UDPv4
iters []enode.Iterator
inputIter enode.Iterator
ch chan *enode.Node
closed chan struct{}
// settings
revalidateInterval time.Duration
}
func newCrawler(input nodeSet, disc *discover.UDPv4, iters ...enode.Iterator) *crawler {
c := &crawler{
input: input,
output: make(nodeSet, len(input)),
disc: disc,
iters: iters,
inputIter: enode.IterNodes(input.nodes()),
ch: make(chan *enode.Node),
closed: make(chan struct{}),
}
c.iters = append(c.iters, c.inputIter)
// Copy input to output initially. Any nodes that fail validation
// will be dropped from output during the run.
for id, n := range input {
c.output[id] = n
}
return c
}
func (c *crawler) run(timeout time.Duration) nodeSet {
var (
timeoutTimer = time.NewTimer(timeout)
timeoutCh <-chan time.Time
doneCh = make(chan enode.Iterator, len(c.iters))
liveIters = len(c.iters)
)
for _, it := range c.iters {
go c.runIterator(doneCh, it)
}
loop:
for {
select {
case n := <-c.ch:
c.updateNode(n)
case it := <-doneCh:
if it == c.inputIter {
// Enable timeout when we're done revalidating the input nodes.
log.Info("Revalidation of input set is done", "len", len(c.input))
if timeout > 0 {
timeoutCh = timeoutTimer.C
}
}
if liveIters--; liveIters == 0 {
break loop
}
case <-timeoutCh:
break loop
}
}
close(c.closed)
for _, it := range c.iters {
it.Close()
}
for ; liveIters > 0; liveIters-- {
<-doneCh
}
return c.output
}
func (c *crawler) runIterator(done chan<- enode.Iterator, it enode.Iterator) {
defer func() { done <- it }()
for it.Next() {
select {
case c.ch <- it.Node():
case <-c.closed:
return
}
}
}
func (c *crawler) updateNode(n *enode.Node) {
node, ok := c.output[n.ID()]
// Skip validation of recently-seen nodes.
if ok && time.Since(node.LastCheck) < c.revalidateInterval {
return
}
// Request the node record.
nn, err := c.disc.RequestENR(n)
node.LastCheck = truncNow()
if err != nil {
if node.Score == 0 {
// Node doesn't implement EIP-868.
log.Debug("Skipping node", "id", n.ID())
return
}
node.Score /= 2
} else {
node.N = nn
node.Seq = nn.Seq()
node.Score++
if node.FirstResponse.IsZero() {
node.FirstResponse = node.LastCheck
}
node.LastResponse = node.LastCheck
}
// Store/update node in output set.
if node.Score <= 0 {
log.Info("Removing node", "id", n.ID())
delete(c.output, n.ID())
} else {
log.Info("Updating node", "id", n.ID(), "seq", n.Seq(), "score", node.Score)
c.output[n.ID()] = node
}
}
func truncNow() time.Time {
return time.Now().UTC().Truncate(1 * time.Second)
}

66
cmd/devp2p/discv4cmd.go
View File

@ -39,6 +39,7 @@ var (
discv4RequestRecordCommand,
discv4ResolveCommand,
discv4ResolveJSONCommand,
discv4CrawlCommand,
},
}
discv4PingCommand = cli.Command{
@ -67,12 +68,25 @@ var (
Flags: []cli.Flag{bootnodesFlag},
ArgsUsage: "<nodes.json file>",
}
discv4CrawlCommand = cli.Command{
Name: "crawl",
Usage: "Updates a nodes.json file with random nodes found in the DHT",
Action: discv4Crawl,
Flags: []cli.Flag{bootnodesFlag, crawlTimeoutFlag},
}
)
var bootnodesFlag = cli.StringFlag{
var (
bootnodesFlag = cli.StringFlag{
Name: "bootnodes",
Usage: "Comma separated nodes used for bootstrapping",
}
}
crawlTimeoutFlag = cli.DurationFlag{
Name: "timeout",
Usage: "Time limit for the crawl.",
Value: 30 * time.Minute,
}
)
func discv4Ping(ctx *cli.Context) error {
n := getNodeArg(ctx)
@ -113,30 +127,48 @@ func discv4ResolveJSON(ctx *cli.Context) error {
if ctx.NArg() < 1 {
return fmt.Errorf("need nodes file as argument")
}
disc := startV4(ctx)
defer disc.Close()
file := ctx.Args().Get(0)
// Load existing nodes in file.
var nodes []*enode.Node
if common.FileExist(file) {
nodes = loadNodesJSON(file).nodes()
nodesFile := ctx.Args().Get(0)
inputSet := make(nodeSet)
if common.FileExist(nodesFile) {
inputSet = loadNodesJSON(nodesFile)
}
// Add nodes from command line arguments.
// Add extra nodes from command line arguments.
var nodeargs []*enode.Node
for i := 1; i < ctx.NArg(); i++ {
n, err := parseNode(ctx.Args().Get(i))
if err != nil {
exit(err)
}
nodes = append(nodes, n)
nodeargs = append(nodeargs, n)
}
result := make(nodeSet, len(nodes))
for _, n := range nodes {
n = disc.Resolve(n)
result[n.ID()] = nodeJSON{Seq: n.Seq(), N: n}
// Run the crawler.
disc := startV4(ctx)
defer disc.Close()
c := newCrawler(inputSet, disc, enode.IterNodes(nodeargs))
c.revalidateInterval = 0
output := c.run(0)
writeNodesJSON(nodesFile, output)
return nil
}
func discv4Crawl(ctx *cli.Context) error {
if ctx.NArg() < 1 {
return fmt.Errorf("need nodes file as argument")
}
writeNodesJSON(file, result)
nodesFile := ctx.Args().First()
var inputSet nodeSet
if common.FileExist(nodesFile) {
inputSet = loadNodesJSON(nodesFile)
}
disc := startV4(ctx)
defer disc.Close()
c := newCrawler(inputSet, disc, disc.RandomNodes())
c.revalidateInterval = 10 * time.Minute
output := c.run(ctx.Duration(crawlTimeoutFlag.Name))
writeNodesJSON(nodesFile, output)
return nil
}

23
cmd/devp2p/dnscmd.go
View File

@ -109,7 +109,8 @@ func dnsSync(ctx *cli.Context) error {
}
def := treeToDefinition(url, t)
def.Meta.LastModified = time.Now()
writeTreeDefinition(outdir, def)
writeTreeMetadata(outdir, def)
writeTreeNodes(outdir, def)
return nil
}
@ -151,7 +152,7 @@ func dnsSign(ctx *cli.Context) error {
def = treeToDefinition(url, t)
def.Meta.LastModified = time.Now()
writeTreeDefinition(defdir, def)
writeTreeMetadata(defdir, def)
return nil
}
@ -315,26 +316,28 @@ func ensureValidTreeSignature(t *dnsdisc.Tree, pubkey *ecdsa.PublicKey, sig stri
return nil
}
// writeTreeDefinition writes a DNS node tree definition to the given directory.
func writeTreeDefinition(directory string, def *dnsDefinition) {
// writeTreeMetadata writes a DNS node tree metadata file to the given directory.
func writeTreeMetadata(directory string, def *dnsDefinition) {
metaJSON, err := json.MarshalIndent(&def.Meta, "", jsonIndent)
if err != nil {
exit(err)
}
// Convert nodes.
nodes := make(nodeSet, len(def.Nodes))
nodes.add(def.Nodes...)
// Write.
if err := os.Mkdir(directory, 0744); err != nil && !os.IsExist(err) {
exit(err)
}
metaFile, nodesFile := treeDefinitionFiles(directory)
writeNodesJSON(nodesFile, nodes)
metaFile, _ := treeDefinitionFiles(directory)
if err := ioutil.WriteFile(metaFile, metaJSON, 0644); err != nil {
exit(err)
}
}
func writeTreeNodes(directory string, def *dnsDefinition) {
ns := make(nodeSet, len(def.Nodes))
ns.add(def.Nodes...)
_, nodesFile := treeDefinitionFiles(directory)
writeNodesJSON(nodesFile, ns)
}
func treeDefinitionFiles(directory string) (string, string) {
meta := filepath.Join(directory, "enrtree-info.json")
nodes := filepath.Join(directory, "nodes.json")

1
cmd/devp2p/main.go
View File

@ -60,6 +60,7 @@ func init() {
enrdumpCommand,
discv4Command,
dnsCommand,
nodesetCommand,
}
}

15
cmd/devp2p/nodeset.go
View File

@ -21,7 +21,9 @@ import (
"encoding/json"
"fmt"
"io/ioutil"
"os"
"sort"
"time"
"github.com/ethereum/go-ethereum/common"
"github.com/ethereum/go-ethereum/p2p/enode"
@ -36,6 +38,15 @@ type nodeSet map[enode.ID]nodeJSON
type nodeJSON struct {
Seq uint64 `json:"seq"`
N *enode.Node `json:"record"`
// The score tracks how many liveness checks were performed. It is incremented by one
// every time the node passes a check, and halved every time it doesn't.
Score int `json:"score,omitempty"`
// These two track the time of last successful contact.
FirstResponse time.Time `json:"firstResponse,omitempty"`
LastResponse time.Time `json:"lastResponse,omitempty"`
// This one tracks the time of our last attempt to contact the node.
LastCheck time.Time `json:"lastCheck,omitempty"`
}
func loadNodesJSON(file string) nodeSet {
@ -51,6 +62,10 @@ func writeNodesJSON(file string, nodes nodeSet) {
if err != nil {
exit(err)
}
if file == "-" {
os.Stdout.Write(nodesJSON)
return
}
if err := ioutil.WriteFile(file, nodesJSON, 0644); err != nil {
exit(err)
}

193
cmd/devp2p/nodesetcmd.go Normal file
View File

@ -0,0 +1,193 @@
// Copyright 2019 The go-ethereum Authors
// This file is part of go-ethereum.
//
// go-ethereum is free software: you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
//
// go-ethereum 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 General Public License for more details.
//
// You should have received a copy of the GNU General Public License
// along with go-ethereum. If not, see <http://www.gnu.org/licenses/>.
package main
import (
"fmt"
"net"
"time"
"github.com/ethereum/go-ethereum/core/forkid"
"github.com/ethereum/go-ethereum/p2p/enr"
"github.com/ethereum/go-ethereum/params"
"github.com/ethereum/go-ethereum/rlp"
"gopkg.in/urfave/cli.v1"
)
var (
nodesetCommand = cli.Command{
Name: "nodeset",
Usage: "Node set tools",
Subcommands: []cli.Command{
nodesetInfoCommand,
nodesetFilterCommand,
},
}
nodesetInfoCommand = cli.Command{
Name: "info",
Usage: "Shows statistics about a node set",
Action: nodesetInfo,
ArgsUsage: "<nodes.json>",
}
nodesetFilterCommand = cli.Command{
Name: "filter",
Usage: "Filters a node set",
Action: nodesetFilter,
ArgsUsage: "<nodes.json> filters..",
SkipFlagParsing: true,
}
)
func nodesetInfo(ctx *cli.Context) error {
if ctx.NArg() < 1 {
return fmt.Errorf("need nodes file as argument")
}
ns := loadNodesJSON(ctx.Args().First())
fmt.Printf("Set contains %d nodes.\n", len(ns))
return nil
}
func nodesetFilter(ctx *cli.Context) error {
if ctx.NArg() < 1 {
return fmt.Errorf("need nodes file as argument")
}
ns := loadNodesJSON(ctx.Args().First())
filter, err := andFilter(ctx.Args().Tail())
if err != nil {
return err
}
result := make(nodeSet)
for id, n := range ns {
if filter(n) {
result[id] = n
}
}
writeNodesJSON("-", result)
return nil
}
type nodeFilter func(nodeJSON) bool
type nodeFilterC struct {
narg int
fn func([]string) (nodeFilter, error)
}
var filterFlags = map[string]nodeFilterC{
"-ip": {1, ipFilter},
"-min-age": {1, minAgeFilter},
"-eth-network": {1, ethFilter},
"-les-server": {0, lesFilter},
}
func parseFilters(args []string) ([]nodeFilter, error) {
var filters []nodeFilter
for len(args) > 0 {
fc, ok := filterFlags[args[0]]
if !ok {
return nil, fmt.Errorf("invalid filter %q", args[0])
}
if len(args) < fc.narg {
return nil, fmt.Errorf("filter %q wants %d arguments, have %d", args[0], fc.narg, len(args))
}
filter, err := fc.fn(args[1:])
if err != nil {
return nil, fmt.Errorf("%s: %v", args[0], err)
}
filters = append(filters, filter)
args = args[fc.narg+1:]
}
return filters, nil
}
func andFilter(args []string) (nodeFilter, error) {
checks, err := parseFilters(args)
if err != nil {
return nil, err
}
f := func(n nodeJSON) bool {
for _, filter := range checks {
if !filter(n) {
return false
}
}
return true
}
return f, nil
}
func ipFilter(args []string) (nodeFilter, error) {
_, cidr, err := net.ParseCIDR(args[0])
if err != nil {
return nil, err
}
f := func(n nodeJSON) bool { return cidr.Contains(n.N.IP()) }
return f, nil
}
func minAgeFilter(args []string) (nodeFilter, error) {
minage, err := time.ParseDuration(args[0])
if err != nil {
return nil, err
}
f := func(n nodeJSON) bool {
age := n.LastResponse.Sub(n.FirstResponse)
return age >= minage
}
return f, nil
}
func ethFilter(args []string) (nodeFilter, error) {
var filter func(forkid.ID) error
switch args[0] {
case "mainnet":
filter = forkid.NewStaticFilter(params.MainnetChainConfig, params.MainnetGenesisHash)
case "rinkeby":
filter = forkid.NewStaticFilter(params.RinkebyChainConfig, params.RinkebyGenesisHash)
case "goerli":
filter = forkid.NewStaticFilter(params.GoerliChainConfig, params.GoerliGenesisHash)
case "ropsten":
filter = forkid.NewStaticFilter(params.TestnetChainConfig, params.TestnetGenesisHash)
default:
return nil, fmt.Errorf("unknown network %q", args[0])
}
f := func(n nodeJSON) bool {
var eth struct {
ForkID forkid.ID
_ []rlp.RawValue `rlp:"tail"`
}
if n.N.Load(enr.WithEntry("eth", &eth)) != nil {
return false
}
return filter(eth.ForkID) == nil
}
return f, nil
}
func lesFilter(args []string) (nodeFilter, error) {
f := func(n nodeJSON) bool {
var les struct {
_ []rlp.RawValue `rlp:"tail"`
}
return n.N.Load(enr.WithEntry("les", &les)) == nil
}
return f, nil
}

8
core/forkid/forkid.go
View File

@ -80,7 +80,7 @@ func newID(config *params.ChainConfig, genesis common.Hash, head uint64) ID {
return ID{Hash: checksumToBytes(hash), Next: next}
}
// NewFilter creates an filter that returns if a fork ID should be rejected or not
// NewFilter creates a filter that returns if a fork ID should be rejected or not
// based on the local chain's status.
func NewFilter(chain *core.BlockChain) func(id ID) error {
return newFilter(
@ -92,6 +92,12 @@ func NewFilter(chain *core.BlockChain) func(id ID) error {
)
}
// NewStaticFilter creates a filter at block zero.
func NewStaticFilter(config *params.ChainConfig, genesis common.Hash) func(id ID) error {
head := func() uint64 { return 0 }
return newFilter(config, genesis, head)
}
// newFilter is the internal version of NewFilter, taking closures as its arguments
// instead of a chain. The reason is to allow testing it without having to simulate
// an entire blockchain.

145
p2p/dial.go
View File

@ -33,12 +33,7 @@ const (
// private networks.
dialHistoryExpiration = inboundThrottleTime + 5*time.Second
// Discovery lookups are throttled and can only run
// once every few seconds.
lookupInterval = 4 * time.Second
// If no peers are found for this amount of time, the initial bootnodes are
// attempted to be connected.
// If no peers are found for this amount of time, the initial bootnodes are dialed.
fallbackInterval = 20 * time.Second
// Endpoint resolution is throttled with bounded backoff.
@ -52,6 +47,10 @@ type NodeDialer interface {
Dial(*enode.Node) (net.Conn, error)
}
type nodeResolver interface {
Resolve(*enode.Node) *enode.Node
}
// TCPDialer implements the NodeDialer interface by using a net.Dialer to
// create TCP connections to nodes in the network
type TCPDialer struct {
@ -69,7 +68,6 @@ func (t TCPDialer) Dial(dest *enode.Node) (net.Conn, error) {
// of the main loop in Server.run.
type dialstate struct {
maxDynDials int
ntab discoverTable
netrestrict *netutil.Netlist
self enode.ID
bootnodes []*enode.Node // default dials when there are no peers
@ -79,55 +77,23 @@ type dialstate struct {
lookupRunning bool
dialing map[enode.ID]connFlag
lookupBuf []*enode.Node // current discovery lookup results
randomNodes []*enode.Node // filled from Table
static map[enode.ID]*dialTask
hist expHeap
}
type discoverTable interface {
Close()
Resolve(*enode.Node) *enode.Node
LookupRandom() []*enode.Node
ReadRandomNodes([]*enode.Node) int
}
type task interface {
Do(*Server)
}
// A dialTask is generated for each node that is dialed. Its
// fields cannot be accessed while the task is running.
type dialTask struct {
flags connFlag
dest *enode.Node
lastResolved time.Time
resolveDelay time.Duration
}
// discoverTask runs discovery table operations.
// Only one discoverTask is active at any time.
// discoverTask.Do performs a random lookup.
type discoverTask struct {
results []*enode.Node
}
// A waitExpireTask is generated if there are no other tasks
// to keep the loop in Server.run ticking.
type waitExpireTask struct {
time.Duration
}
func newDialState(self enode.ID, ntab discoverTable, maxdyn int, cfg *Config) *dialstate {
func newDialState(self enode.ID, maxdyn int, cfg *Config) *dialstate {
s := &dialstate{
maxDynDials: maxdyn,
ntab: ntab,
self: self,
netrestrict: cfg.NetRestrict,
log: cfg.Logger,
static: make(map[enode.ID]*dialTask),
dialing: make(map[enode.ID]connFlag),
bootnodes: make([]*enode.Node, len(cfg.BootstrapNodes)),
randomNodes: make([]*enode.Node, maxdyn/2),
}
copy(s.bootnodes, cfg.BootstrapNodes)
if s.log == nil {
@ -151,10 +117,6 @@ func (s *dialstate) removeStatic(n *enode.Node) {
}
func (s *dialstate) newTasks(nRunning int, peers map[enode.ID]*Peer, now time.Time) []task {
if s.start.IsZero() {
s.start = now
}
var newtasks []task
addDial := func(flag connFlag, n *enode.Node) bool {
if err := s.checkDial(n, peers); err != nil {
@ -166,20 +128,9 @@ func (s *dialstate) newTasks(nRunning int, peers map[enode.ID]*Peer, now time.Ti
return true
}
// Compute number of dynamic dials necessary at this point.
needDynDials := s.maxDynDials
for _, p := range peers {
if p.rw.is(dynDialedConn) {
needDynDials--
if s.start.IsZero() {
s.start = now
}
}
for _, flag := range s.dialing {
if flag&dynDialedConn != 0 {
needDynDials--
}
}
// Expire the dial history on every invocation.
s.hist.expire(now)
// Create dials for static nodes if they are not connected.
@ -194,6 +145,20 @@ func (s *dialstate) newTasks(nRunning int, peers map[enode.ID]*Peer, now time.Ti
newtasks = append(newtasks, t)
}
}
// Compute number of dynamic dials needed.
needDynDials := s.maxDynDials
for _, p := range peers {
if p.rw.is(dynDialedConn) {
needDynDials--
}
}
for _, flag := range s.dialing {
if flag&dynDialedConn != 0 {
needDynDials--
}
}
// If we don't have any peers whatsoever, try to dial a random bootnode. This
// scenario is useful for the testnet (and private networks) where the discovery
// table might be full of mostly bad peers, making it hard to find good ones.
@ -201,24 +166,12 @@ func (s *dialstate) newTasks(nRunning int, peers map[enode.ID]*Peer, now time.Ti
bootnode := s.bootnodes[0]
s.bootnodes = append(s.bootnodes[:0], s.bootnodes[1:]...)
s.bootnodes = append(s.bootnodes, bootnode)
if addDial(dynDialedConn, bootnode) {
needDynDials--
}
}
// Use random nodes from the table for half of the necessary
// dynamic dials.
randomCandidates := needDynDials / 2
if randomCandidates > 0 {
n := s.ntab.ReadRandomNodes(s.randomNodes)
for i := 0; i < randomCandidates && i < n; i++ {
if addDial(dynDialedConn, s.randomNodes[i]) {
needDynDials--
}
}
}
// Create dynamic dials from random lookup results, removing tried
// items from the result buffer.
// Create dynamic dials from discovery results.
i := 0
for ; i < len(s.lookupBuf) && needDynDials > 0; i++ {
if addDial(dynDialedConn, s.lookupBuf[i]) {
@ -226,10 +179,11 @@ func (s *dialstate) newTasks(nRunning int, peers map[enode.ID]*Peer, now time.Ti
}
}
s.lookupBuf = s.lookupBuf[:copy(s.lookupBuf, s.lookupBuf[i:])]
// Launch a discovery lookup if more candidates are needed.
if len(s.lookupBuf) < needDynDials && !s.lookupRunning {
s.lookupRunning = true
newtasks = append(newtasks, &discoverTask{})
newtasks = append(newtasks, &discoverTask{want: needDynDials - len(s.lookupBuf)})
}
// Launch a timer to wait for the next node to expire if all
@ -279,6 +233,15 @@ func (s *dialstate) taskDone(t task, now time.Time) {
}
}
// A dialTask is generated for each node that is dialed. Its
// fields cannot be accessed while the task is running.
type dialTask struct {
flags connFlag
dest *enode.Node
lastResolved time.Time
resolveDelay time.Duration
}
func (t *dialTask) Do(srv *Server) {
if t.dest.Incomplete() {
if !t.resolve(srv) {
@ -304,8 +267,8 @@ func (t *dialTask) Do(srv *Server) {
// discovery network with useless queries for nodes that don't exist.
// The backoff delay resets when the node is found.
func (t *dialTask) resolve(srv *Server) bool {
if srv.ntab == nil {
srv.log.Debug("Can't resolve node", "id", t.dest.ID, "err", "discovery is disabled")
if srv.staticNodeResolver == nil {
srv.log.Debug("Can't resolve node", "id", t.dest.ID(), "err", "discovery is disabled")
return false
}
if t.resolveDelay == 0 {
@ -314,20 +277,20 @@ func (t *dialTask) resolve(srv *Server) bool {
if time.Since(t.lastResolved) < t.resolveDelay {
return false
}
resolved := srv.ntab.Resolve(t.dest)
resolved := srv.staticNodeResolver.Resolve(t.dest)
t.lastResolved = time.Now()
if resolved == nil {
t.resolveDelay *= 2
if t.resolveDelay > maxResolveDelay {
t.resolveDelay = maxResolveDelay
}
srv.log.Debug("Resolving node failed", "id", t.dest.ID, "newdelay", t.resolveDelay)
srv.log.Debug("Resolving node failed", "id", t.dest.ID(), "newdelay", t.resolveDelay)
return false
}
// The node was found.
t.resolveDelay = initialResolveDelay
t.dest = resolved
srv.log.Debug("Resolved node", "id", t.dest.ID, "addr", &net.TCPAddr{IP: t.dest.IP(), Port: t.dest.TCP()})
srv.log.Debug("Resolved node", "id", t.dest.ID(), "addr", &net.TCPAddr{IP: t.dest.IP(), Port: t.dest.TCP()})
return true
}
@ -350,26 +313,34 @@ func (t *dialTask) String() string {
return fmt.Sprintf("%v %x %v:%d", t.flags, id[:8], t.dest.IP(), t.dest.TCP())
}
// discoverTask runs discovery table operations.
// Only one discoverTask is active at any time.
// discoverTask.Do performs a random lookup.
type discoverTask struct {
want int
results []*enode.Node
}
func (t *discoverTask) Do(srv *Server) {
// newTasks generates a lookup task whenever dynamic dials are
// necessary. Lookups need to take some time, otherwise the
// event loop spins too fast.
next := srv.lastLookup.Add(lookupInterval)
if now := time.Now(); now.Before(next) {
time.Sleep(next.Sub(now))
}
srv.lastLookup = time.Now()
t.results = srv.ntab.LookupRandom()
t.results = enode.ReadNodes(srv.discmix, t.want)
}
func (t *discoverTask) String() string {
s := "discovery lookup"
s := "discovery query"
if len(t.results) > 0 {
s += fmt.Sprintf(" (%d results)", len(t.results))
} else {
s += fmt.Sprintf(" (want %d)", t.want)
}
return s
}
// A waitExpireTask is generated if there are no other tasks
// to keep the loop in Server.run ticking.
type waitExpireTask struct {
time.Duration
}
func (t waitExpireTask) Do(*Server) {
time.Sleep(t.Duration)
}

213
p2p/dial_test.go
View File

@ -73,7 +73,7 @@ func runDialTest(t *testing.T, test dialtest) {
t.Errorf("ERROR round %d: got %v\nwant %v\nstate: %v\nrunning: %v",
i, spew.Sdump(new), spew.Sdump(round.new), spew.Sdump(test.init), spew.Sdump(running))
}
t.Logf("round %d new tasks: %s", i, strings.TrimSpace(spew.Sdump(new)))
t.Logf("round %d (running %d) new tasks: %s", i, running, strings.TrimSpace(spew.Sdump(new)))
// Time advances by 16 seconds on every round.
vtime = vtime.Add(16 * time.Second)
@ -81,19 +81,11 @@ func runDialTest(t *testing.T, test dialtest) {
}
}
type fakeTable []*enode.Node
func (t fakeTable) Self() *enode.Node { return new(enode.Node) }
func (t fakeTable) Close() {}
func (t fakeTable) LookupRandom() []*enode.Node { return nil }
func (t fakeTable) Resolve(*enode.Node) *enode.Node { return nil }
func (t fakeTable) ReadRandomNodes(buf []*enode.Node) int { return copy(buf, t) }
// This test checks that dynamic dials are launched from discovery results.
func TestDialStateDynDial(t *testing.T) {
config := &Config{Logger: testlog.Logger(t, log.LvlTrace)}
runDialTest(t, dialtest{
init: newDialState(enode.ID{}, fakeTable{}, 5, config),
init: newDialState(enode.ID{}, 5, config),
rounds: []round{
// A discovery query is launched.
{
@ -102,7 +94,9 @@ func TestDialStateDynDial(t *testing.T) {
{rw: &conn{flags: dynDialedConn, node: newNode(uintID(1), nil)}},
{rw: &conn{flags: dynDialedConn, node: newNode(uintID(2), nil)}},
},
new: []task{&discoverTask{}},
new: []task{
&discoverTask{want: 3},
},
},
// Dynamic dials are launched when it completes.
{
@ -188,7 +182,7 @@ func TestDialStateDynDial(t *testing.T) {
},
new: []task{
&dialTask{flags: dynDialedConn, dest: newNode(uintID(7), nil)},
&discoverTask{},
&discoverTask{want: 2},
},
},
// Peer 7 is connected, but there still aren't enough dynamic peers
@ -218,7 +212,7 @@ func TestDialStateDynDial(t *testing.T) {
&discoverTask{},
},
new: []task{
&discoverTask{},
&discoverTask{want: 2},
},
},
},
@ -235,35 +229,37 @@ func TestDialStateDynDialBootnode(t *testing.T) {
},
Logger: testlog.Logger(t, log.LvlTrace),
}
table := fakeTable{
runDialTest(t, dialtest{
init: newDialState(enode.ID{}, 5, config),
rounds: []round{
{
new: []task{
&discoverTask{want: 5},
},
},
{
done: []task{
&discoverTask{
results: []*enode.Node{
newNode(uintID(4), nil),
newNode(uintID(5), nil),
newNode(uintID(6), nil),
newNode(uintID(7), nil),
newNode(uintID(8), nil),
}
runDialTest(t, dialtest{
init: newDialState(enode.ID{}, table, 5, config),
rounds: []round{
// 2 dynamic dials attempted, bootnodes pending fallback interval
{
},
},
},
new: []task{
&dialTask{flags: dynDialedConn, dest: newNode(uintID(4), nil)},
&dialTask{flags: dynDialedConn, dest: newNode(uintID(5), nil)},
&discoverTask{},
&discoverTask{want: 3},
},
},
// No dials succeed, bootnodes still pending fallback interval
{},
// 1 bootnode attempted as fallback interval was reached
{
done: []task{
&dialTask{flags: dynDialedConn, dest: newNode(uintID(4), nil)},
&dialTask{flags: dynDialedConn, dest: newNode(uintID(5), nil)},
},
},
// No dials succeed, bootnodes still pending fallback interval
{},
// No dials succeed, 2 dynamic dials attempted and 1 bootnode too as fallback interval was reached
{
new: []task{
&dialTask{flags: dynDialedConn, dest: newNode(uintID(1), nil)},
},
@ -275,15 +271,12 @@ func TestDialStateDynDialBootnode(t *testing.T) {
},
new: []task{
&dialTask{flags: dynDialedConn, dest: newNode(uintID(2), nil)},
&dialTask{flags: dynDialedConn, dest: newNode(uintID(4), nil)},
&dialTask{flags: dynDialedConn, dest: newNode(uintID(5), nil)},
},
},
// No dials succeed, 3rd bootnode is attempted
{
done: []task{
&dialTask{flags: dynDialedConn, dest: newNode(uintID(2), nil)},
&dialTask{flags: dynDialedConn, dest: newNode(uintID(5), nil)},
},
new: []task{
&dialTask{flags: dynDialedConn, dest: newNode(uintID(3), nil)},
@ -293,115 +286,19 @@ func TestDialStateDynDialBootnode(t *testing.T) {
{
done: []task{
&dialTask{flags: dynDialedConn, dest: newNode(uintID(3), nil)},
},
new: []task{},
},
// Random dial succeeds, no more bootnodes are attempted
{
new: []task{
&waitExpireTask{3 * time.Second},
},
peers: []*Peer{
{rw: &conn{flags: dynDialedConn, node: newNode(uintID(4), nil)}},
},
done: []task{
&dialTask{flags: dynDialedConn, dest: newNode(uintID(1), nil)},
&dialTask{flags: dynDialedConn, dest: newNode(uintID(4), nil)},
},
},
},
})
}
func TestDialStateDynDialFromTable(t *testing.T) {
// This table always returns the same random nodes
// in the order given below.
table := fakeTable{
newNode(uintID(1), nil),
newNode(uintID(2), nil),
newNode(uintID(3), nil),
newNode(uintID(4), nil),
newNode(uintID(5), nil),
newNode(uintID(6), nil),
newNode(uintID(7), nil),
newNode(uintID(8), nil),
}
runDialTest(t, dialtest{
init: newDialState(enode.ID{}, table, 10, &Config{Logger: testlog.Logger(t, log.LvlTrace)}),
rounds: []round{
// 5 out of 8 of the nodes returned by ReadRandomNodes are dialed.
{
new: []task{
&dialTask{flags: dynDialedConn, dest: newNode(uintID(1), nil)},
&dialTask{flags: dynDialedConn, dest: newNode(uintID(2), nil)},
&dialTask{flags: dynDialedConn, dest: newNode(uintID(3), nil)},
&dialTask{flags: dynDialedConn, dest: newNode(uintID(4), nil)},
&dialTask{flags: dynDialedConn, dest: newNode(uintID(5), nil)},
&discoverTask{},
},
},
// Dialing nodes 1,2 succeeds. Dials from the lookup are launched.
{
peers: []*Peer{
{rw: &conn{flags: dynDialedConn, node: newNode(uintID(1), nil)}},
{rw: &conn{flags: dynDialedConn, node: newNode(uintID(2), nil)}},
},
done: []task{
&dialTask{flags: dynDialedConn, dest: newNode(uintID(1), nil)},
&dialTask{flags: dynDialedConn, dest: newNode(uintID(2), nil)},
&discoverTask{results: []*enode.Node{
newNode(uintID(10), nil),
newNode(uintID(11), nil),
newNode(uintID(12), nil),
newNode(uintID(6), nil),
}},
},
new: []task{
&dialTask{flags: dynDialedConn, dest: newNode(uintID(10), nil)},
&dialTask{flags: dynDialedConn, dest: newNode(uintID(11), nil)},
&dialTask{flags: dynDialedConn, dest: newNode(uintID(12), nil)},
&discoverTask{},
&dialTask{flags: dynDialedConn, dest: newNode(uintID(6), nil)},
&discoverTask{want: 4},
},
},
// Dialing nodes 3,4,5 fails. The dials from the lookup succeed.
// Random dial succeeds, no more bootnodes are attempted
{
peers: []*Peer{
{rw: &conn{flags: dynDialedConn, node: newNode(uintID(1), nil)}},
{rw: &conn{flags: dynDialedConn, node: newNode(uintID(2), nil)}},
{rw: &conn{flags: dynDialedConn, node: newNode(uintID(10), nil)}},
{rw: &conn{flags: dynDialedConn, node: newNode(uintID(11), nil)}},
{rw: &conn{flags: dynDialedConn, node: newNode(uintID(12), nil)}},
},
done: []task{
&dialTask{flags: dynDialedConn, dest: newNode(uintID(3), nil)},
&dialTask{flags: dynDialedConn, dest: newNode(uintID(4), nil)},
&dialTask{flags: dynDialedConn, dest: newNode(uintID(5), nil)},
&dialTask{flags: dynDialedConn, dest: newNode(uintID(10), nil)},
&dialTask{flags: dynDialedConn, dest: newNode(uintID(11), nil)},
&dialTask{flags: dynDialedConn, dest: newNode(uintID(12), nil)},
},
},
// Waiting for expiry. No waitExpireTask is launched because the
// discovery query is still running.
{
peers: []*Peer{
{rw: &conn{flags: dynDialedConn, node: newNode(uintID(1), nil)}},
{rw: &conn{flags: dynDialedConn, node: newNode(uintID(2), nil)}},
{rw: &conn{flags: dynDialedConn, node: newNode(uintID(10), nil)}},
{rw: &conn{flags: dynDialedConn, node: newNode(uintID(11), nil)}},
{rw: &conn{flags: dynDialedConn, node: newNode(uintID(12), nil)}},
},
},
// Nodes 3,4 are not tried again because only the first two
// returned random nodes (nodes 1,2) are tried and they're
// already connected.
{
peers: []*Peer{
{rw: &conn{flags: dynDialedConn, node: newNode(uintID(1), nil)}},
{rw: &conn{flags: dynDialedConn, node: newNode(uintID(2), nil)}},
{rw: &conn{flags: dynDialedConn, node: newNode(uintID(10), nil)}},
{rw: &conn{flags: dynDialedConn, node: newNode(uintID(11), nil)}},
{rw: &conn{flags: dynDialedConn, node: newNode(uintID(12), nil)}},
{rw: &conn{flags: dynDialedConn, node: newNode(uintID(6), nil)}},
},
},
},
@ -416,11 +313,11 @@ func newNode(id enode.ID, ip net.IP) *enode.Node {
return enode.SignNull(&r, id)
}
// This test checks that candidates that do not match the netrestrict list are not dialed.
// // This test checks that candidates that do not match the netrestrict list are not dialed.
func TestDialStateNetRestrict(t *testing.T) {
// This table always returns the same random nodes
// in the order given below.
table := fakeTable{
nodes := []*enode.Node{
newNode(uintID(1), net.ParseIP("127.0.0.1")),
newNode(uintID(2), net.ParseIP("127.0.0.2")),
newNode(uintID(3), net.ParseIP("127.0.0.3")),
@ -434,12 +331,23 @@ func TestDialStateNetRestrict(t *testing.T) {
restrict.Add("127.0.2.0/24")
runDialTest(t, dialtest{
init: newDialState(enode.ID{}, table, 10, &Config{NetRestrict: restrict}),
init: newDialState(enode.ID{}, 10, &Config{NetRestrict: restrict}),
rounds: []round{
{
new: []task{
&dialTask{flags: dynDialedConn, dest: table[4]},
&discoverTask{},
&discoverTask{want: 10},
},
},
{
done: []task{
&discoverTask{results: nodes},
},
new: []task{
&dialTask{flags: dynDialedConn, dest: nodes[4]},
&dialTask{flags: dynDialedConn, dest: nodes[5]},
&dialTask{flags: dynDialedConn, dest: nodes[6]},
&dialTask{flags: dynDialedConn, dest: nodes[7]},
&discoverTask{want: 6},
},
},
},
@ -459,7 +367,7 @@ func TestDialStateStaticDial(t *testing.T) {
Logger: testlog.Logger(t, log.LvlTrace),
}
runDialTest(t, dialtest{
init: newDialState(enode.ID{}, fakeTable{}, 0, config),
init: newDialState(enode.ID{}, 0, config),
rounds: []round{
// Static dials are launched for the nodes that
// aren't yet connected.
@ -544,7 +452,7 @@ func TestDialStateCache(t *testing.T) {
Logger: testlog.Logger(t, log.LvlTrace),
}
runDialTest(t, dialtest{
init: newDialState(enode.ID{}, fakeTable{}, 0, config),
init: newDialState(enode.ID{}, 0, config),
rounds: []round{
// Static dials are launched for the nodes that
// aren't yet connected.
@ -618,8 +526,8 @@ func TestDialResolve(t *testing.T) {
Dialer: TCPDialer{&net.Dialer{Deadline: time.Now().Add(-5 * time.Minute)}},
}
resolved := newNode(uintID(1), net.IP{127, 0, 55, 234})
table := &resolveMock{answer: resolved}
state := newDialState(enode.ID{}, table, 0, config)
resolver := &resolveMock{answer: resolved}
state := newDialState(enode.ID{}, 0, config)
// Check that the task is generated with an incomplete ID.
dest := newNode(uintID(1), nil)
@ -630,10 +538,14 @@ func TestDialResolve(t *testing.T) {
}
// Now run the task, it should resolve the ID once.
srv := &Server{ntab: table, log: config.Logger, Config: *config}
srv := &Server{
Config: *config,
log: config.Logger,
staticNodeResolver: resolver,
}
tasks[0].Do(srv)
if !reflect.DeepEqual(table.resolveCalls, []*enode.Node{dest}) {
t.Fatalf("wrong resolve calls, got %v", table.resolveCalls)
if !reflect.DeepEqual(resolver.calls, []*enode.Node{dest}) {
t.Fatalf("wrong resolve calls, got %v", resolver.calls)
}
// Report it as done to the dialer, which should update the static node record.
@ -666,18 +578,13 @@ func uintID(i uint32) enode.ID {
return id
}
// implements discoverTable for TestDialResolve
// for TestDialResolve
type resolveMock struct {
resolveCalls []*enode.Node
calls []*enode.Node
answer *enode.Node
}
func (t *resolveMock) Resolve(n *enode.Node) *enode.Node {
t.resolveCalls = append(t.resolveCalls, n)
t.calls = append(t.calls, n)
return t.answer
}
func (t *resolveMock) Self() *enode.Node { return new(enode.Node) }
func (t *resolveMock) Close() {}
func (t *resolveMock) LookupRandom() []*enode.Node { return nil }
func (t *resolveMock) ReadRandomNodes(buf []*enode.Node) int { return 0 }

5
p2p/discover/common.go
View File

@ -25,6 +25,7 @@ import (
"github.com/ethereum/go-ethereum/p2p/netutil"
)
// UDPConn is a network connection on which discovery can operate.
type UDPConn interface {
ReadFromUDP(b []byte) (n int, addr *net.UDPAddr, err error)
WriteToUDP(b []byte, addr *net.UDPAddr) (n int, err error)
@ -32,7 +33,7 @@ type UDPConn interface {
LocalAddr() net.Addr
}
// Config holds Table-related settings.
// Config holds settings for the discovery listener.
type Config struct {
// These settings are required and configure the UDP listener:
PrivateKey *ecdsa.PrivateKey
@ -50,7 +51,7 @@ func ListenUDP(c UDPConn, ln *enode.LocalNode, cfg Config) (*UDPv4, error) {
}
// ReadPacket is a packet that couldn't be handled. Those packets are sent to the unhandled
// channel if configured.
// channel if configured. This is exported for internal use, do not use this type.
type ReadPacket struct {
Data []byte
Addr *net.UDPAddr

209
p2p/discover/lookup.go Normal file
View File

@ -0,0 +1,209 @@
// Copyright 2019 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 (
"context"
"github.com/ethereum/go-ethereum/p2p/enode"
)
// lookup performs a network search for nodes close to the given target. It approaches the
// target by querying nodes that are closer to it on each iteration. The given target does
// not need to be an actual node identifier.
type lookup struct {
tab *Table
queryfunc func(*node) ([]*node, error)
replyCh chan []*node
cancelCh <-chan struct{}
asked, seen map[enode.ID]bool
result nodesByDistance
replyBuffer []*node
queries int
}
type queryFunc func(*node) ([]*node, error)
func newLookup(ctx context.Context, tab *Table, target enode.ID, q queryFunc) *lookup {
it := &lookup{
tab: tab,
queryfunc: q,
asked: make(map[enode.ID]bool),
seen: make(map[enode.ID]bool),
result: nodesByDistance{target: target},
replyCh: make(chan []*node, alpha),
cancelCh: ctx.Done(),
queries: -1,
}
// Don't query further if we hit ourself.
// Unlikely to happen often in practice.
it.asked[tab.self().ID()] = true
return it
}
// run runs the lookup to completion and returns the closest nodes found.
func (it *lookup) run() []*enode.Node {
for it.advance() {
}
return unwrapNodes(it.result.entries)
}
// advance advances the lookup until any new nodes have been found.
// It returns false when the lookup has ended.
func (it *lookup) advance() bool {
for it.startQueries() {
select {
case nodes := <-it.replyCh:
it.replyBuffer = it.replyBuffer[:0]
for _, n := range nodes {
if n != nil && !it.seen[n.ID()] {
it.seen[n.ID()] = true
it.result.push(n, bucketSize)
it.replyBuffer = append(it.replyBuffer, n)
}
}
it.queries--
if len(it.replyBuffer) > 0 {
return true
}
case <-it.cancelCh:
it.shutdown()
}
}
return false
}
func (it *lookup) shutdown() {
for it.queries > 0 {
<-it.replyCh
it.queries--
}
it.queryfunc = nil
it.replyBuffer = nil
}
func (it *lookup) startQueries() bool {
if it.queryfunc == nil {
return false
}
// The first query returns nodes from the local table.
if it.queries == -1 {
it.tab.mutex.Lock()
closest := it.tab.closest(it.result.target, bucketSize, false)
it.tab.mutex.Unlock()
it.queries = 1
it.replyCh <- closest.entries
return true
}
// Ask the closest nodes that we haven't asked yet.
for i := 0; i < len(it.result.entries) && it.queries < alpha; i++ {
n := it.result.entries[i]
if !it.asked[n.ID()] {
it.asked[n.ID()] = true
it.queries++
go it.query(n, it.replyCh)
}
}
// The lookup ends when no more nodes can be asked.
return it.queries > 0
}
func (it *lookup) query(n *node, reply chan<- []*node) {
fails := it.tab.db.FindFails(n.ID(), n.IP())
r, err := it.queryfunc(n)
if err == errClosed {
// Avoid recording failures on shutdown.
reply <- nil
return
} else if len(r) == 0 {
fails++
it.tab.db.UpdateFindFails(n.ID(), n.IP(), fails)
it.tab.log.Trace("Findnode failed", "id", n.ID(), "failcount", fails, "err", err)
if fails >= maxFindnodeFailures {
it.tab.log.Trace("Too many findnode failures, dropping", "id", n.ID(), "failcount", fails)
it.tab.delete(n)
}
} else if fails > 0 {
// Reset failure counter because it counts _consecutive_ failures.
it.tab.db.UpdateFindFails(n.ID(), n.IP(), 0)
}
// Grab as many nodes as possible. Some of them might not be alive anymore, but we'll
// just remove those again during revalidation.
for _, n := range r {
it.tab.addSeenNode(n)
}
reply <- r
}
// lookupIterator performs lookup operations and iterates over all seen nodes.
// When a lookup finishes, a new one is created through nextLookup.
type lookupIterator struct {
buffer []*node
nextLookup lookupFunc
ctx context.Context
cancel func()
lookup *lookup
}
type lookupFunc func(ctx context.Context) *lookup
func newLookupIterator(ctx context.Context, next lookupFunc) *lookupIterator {
ctx, cancel := context.WithCancel(ctx)
return &lookupIterator{ctx: ctx, cancel: cancel, nextLookup: next}
}
// Node returns the current node.
func (it *lookupIterator) Node() *enode.Node {
if len(it.buffer) == 0 {
return nil
}
return unwrapNode(it.buffer[0])
}
// Next moves to the next node.
func (it *lookupIterator) Next() bool {
// Consume next node in buffer.
if len(it.buffer) > 0 {
it.buffer = it.buffer[1:]
}
// Advance the lookup to refill the buffer.
for len(it.buffer) == 0 {
if it.ctx.Err() != nil {
it.lookup = nil
it.buffer = nil
return false
}
if it.lookup == nil {
it.lookup = it.nextLookup(it.ctx)
continue
}
if !it.lookup.advance() {
it.lookup = nil
continue
}
it.buffer = it.lookup.replyBuffer
}
return true
}
// Close ends the iterator.
func (it *lookupIterator) Close() {
it.cancel()
}

25
p2p/discover/table_util_test.go
View File

@ -17,11 +17,14 @@
package discover
import (
"bytes"
"crypto/ecdsa"
"encoding/hex"
"errors"
"fmt"
"math/rand"
"net"
"reflect"
"sort"
"sync"
@ -169,6 +172,28 @@ func hasDuplicates(slice []*node) bool {
return false
}
func checkNodesEqual(got, want []*enode.Node) error {
if reflect.DeepEqual(got, want) {
return nil
}
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 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

124
p2p/discover/v4_udp_lookup_test.go → p2p/discover/v4_lookup_test.go
View File

@ -20,7 +20,6 @@ import (
"crypto/ecdsa"
"fmt"
"net"
"reflect"
"sort"
"testing"
@ -49,19 +48,7 @@ func TestUDPv4_Lookup(t *testing.T) {
}()
// Answer lookup packets.
for done := false; !done; {
done = test.waitPacketOut(func(p packetV4, to *net.UDPAddr, hash []byte) {
n, key := lookupTestnet.nodeByAddr(to)
switch p.(type) {
case *pingV4:
test.packetInFrom(nil, key, to, &pongV4{Expiration: futureExp, ReplyTok: hash})
case *findnodeV4:
dist := enode.LogDist(n.ID(), lookupTestnet.target.id())
nodes := lookupTestnet.nodesAtDistance(dist - 1)
test.packetInFrom(nil, key, to, &neighborsV4{Expiration: futureExp, Nodes: nodes})
}
})
}
serveTestnet(test, lookupTestnet)
// Verify result nodes.
results := <-resultC
@ -78,8 +65,94 @@ func TestUDPv4_Lookup(t *testing.T) {
if !sortedByDistanceTo(lookupTestnet.target.id(), wrapNodes(results)) {
t.Errorf("result set not sorted by distance to target")
}
if !reflect.DeepEqual(results, lookupTestnet.closest(bucketSize)) {
t.Errorf("results aren't the closest %d nodes", bucketSize)
if err := checkNodesEqual(results, lookupTestnet.closest(bucketSize)); err != nil {
t.Errorf("results aren't the closest %d nodes\n%v", bucketSize, err)
}
}
func TestUDPv4_LookupIterator(t *testing.T) {
t.Parallel()
test := newUDPTest(t)
defer test.close()
// Seed table with initial nodes.
bootnodes := make([]*node, len(lookupTestnet.dists[256]))
for i := range lookupTestnet.dists[256] {
bootnodes[i] = wrapNode(lookupTestnet.node(256, i))
}
fillTable(test.table, bootnodes)
go serveTestnet(test, lookupTestnet)
// Create the iterator and collect the nodes it yields.
iter := test.udp.RandomNodes()
seen := make(map[enode.ID]*enode.Node)
for limit := lookupTestnet.len(); iter.Next() && len(seen) < limit; {
seen[iter.Node().ID()] = iter.Node()
}
iter.Close()
// Check that all nodes in lookupTestnet were seen by the iterator.
results := make([]*enode.Node, 0, len(seen))
for _, n := range seen {
results = append(results, n)
}
sortByID(results)
want := lookupTestnet.nodes()
if err := checkNodesEqual(results, want); err != nil {
t.Fatal(err)
}
}
// TestUDPv4_LookupIteratorClose checks that lookupIterator ends when its Close
// method is called.
func TestUDPv4_LookupIteratorClose(t *testing.T) {
t.Parallel()
test := newUDPTest(t)
defer test.close()
// Seed table with initial nodes.
bootnodes := make([]*node, len(lookupTestnet.dists[256]))
for i := range lookupTestnet.dists[256] {
bootnodes[i] = wrapNode(lookupTestnet.node(256, i))
}
fillTable(test.table, bootnodes)
go serveTestnet(test, lookupTestnet)
it := test.udp.RandomNodes()
if ok := it.Next(); !ok || it.Node() == nil {
t.Fatalf("iterator didn't return any node")
}
it.Close()
ncalls := 0
for ; ncalls < 100 && it.Next(); ncalls++ {
if it.Node() == nil {
t.Error("iterator returned Node() == nil node after Next() == true")
}
}
t.Logf("iterator returned %d nodes after close", ncalls)
if it.Next() {
t.Errorf("Next() == true after close and %d more calls", ncalls)
}
if n := it.Node(); n != nil {
t.Errorf("iterator returned non-nil node after close and %d more calls", ncalls)
}
}
func serveTestnet(test *udpTest, testnet *preminedTestnet) {
for done := false; !done; {
done = test.waitPacketOut(func(p packetV4, to *net.UDPAddr, hash []byte) {
n, key := testnet.nodeByAddr(to)
switch p.(type) {
case *pingV4:
test.packetInFrom(nil, key, to, &pongV4{Expiration: futureExp, ReplyTok: hash})
case *findnodeV4:
dist := enode.LogDist(n.ID(), testnet.target.id())
nodes := testnet.nodesAtDistance(dist - 1)
test.packetInFrom(nil, key, to, &neighborsV4{Expiration: futureExp, Nodes: nodes})
}
})
}
}
@ -148,6 +221,25 @@ type preminedTestnet struct {
dists [hashBits + 1][]*ecdsa.PrivateKey
}
func (tn *preminedTestnet) len() int {
n := 0
for _, keys := range tn.dists {
n += len(keys)
}
return n
}
func (tn *preminedTestnet) nodes() []*enode.Node {
result := make([]*enode.Node, 0, tn.len())
for dist, keys := range tn.dists {
for index := range keys {
result = append(result, tn.node(dist, index))
}
}
sortByID(result)
return result
}
func (tn *preminedTestnet) node(dist, index int) *enode.Node {
key := tn.dists[dist][index]
ip := net.IP{127, byte(dist >> 8), byte(dist), byte(index)}

169
p2p/discover/v4_udp.go
View File

@ -19,6 +19,7 @@ package discover
import (
"bytes"
"container/list"
"context"
"crypto/ecdsa"
crand "crypto/rand"
"errors"
@ -207,7 +208,8 @@ type UDPv4 struct {
addReplyMatcher chan *replyMatcher
gotreply chan reply
closing chan struct{}
closeCtx context.Context
cancelCloseCtx func()
}
// replyMatcher represents a pending reply.
@ -256,20 +258,23 @@ type reply struct {
}
func ListenV4(c UDPConn, ln *enode.LocalNode, cfg Config) (*UDPv4, error) {
closeCtx, cancel := context.WithCancel(context.Background())
t := &UDPv4{
conn: c,
priv: cfg.PrivateKey,
netrestrict: cfg.NetRestrict,
localNode: ln,
db: ln.Database(),
closing: make(chan struct{}),
gotreply: make(chan reply),
addReplyMatcher: make(chan *replyMatcher),
closeCtx: closeCtx,
cancelCloseCtx: cancel,
log: cfg.Log,
}
if t.log == nil {
t.log = log.Root()
}
tab, err := newTable(t, ln.Database(), cfg.Bootnodes, t.log)
if err != nil {
return nil, err
@ -291,126 +296,13 @@ func (t *UDPv4) Self() *enode.Node {
// Close shuts down the socket and aborts any running queries.
func (t *UDPv4) Close() {
t.closeOnce.Do(func() {
close(t.closing)
t.cancelCloseCtx()
t.conn.Close()
t.wg.Wait()
t.tab.close()
})
}
// ReadRandomNodes reads random nodes from the local table.
func (t *UDPv4) ReadRandomNodes(buf []*enode.Node) int {
return t.tab.ReadRandomNodes(buf)
}
// LookupRandom finds random nodes in the network.
func (t *UDPv4) LookupRandom() []*enode.Node {
if t.tab.len() == 0 {
// All nodes were dropped, refresh. The very first query will hit this
// case and run the bootstrapping logic.
<-t.tab.refresh()
}
return t.lookupRandom()
}
func (t *UDPv4) LookupPubkey(key *ecdsa.PublicKey) []*enode.Node {
if t.tab.len() == 0 {
// All nodes were dropped, refresh. The very first query will hit this
// case and run the bootstrapping logic.
<-t.tab.refresh()
}
return unwrapNodes(t.lookup(encodePubkey(key)))
}
func (t *UDPv4) lookupRandom() []*enode.Node {
var target encPubkey
crand.Read(target[:])
return unwrapNodes(t.lookup(target))
}
func (t *UDPv4) lookupSelf() []*enode.Node {
return unwrapNodes(t.lookup(encodePubkey(&t.priv.PublicKey)))
}
// lookup performs a network search for nodes close to the given target. It approaches the
// target by querying nodes that are closer to it on each iteration. The given target does
// not need to be an actual node identifier.
func (t *UDPv4) lookup(targetKey encPubkey) []*node {
var (
target = enode.ID(crypto.Keccak256Hash(targetKey[:]))
asked = make(map[enode.ID]bool)
seen = make(map[enode.ID]bool)
reply = make(chan []*node, alpha)
pendingQueries = 0
result *nodesByDistance
)
// Don't query further if we hit ourself.
// Unlikely to happen often in practice.
asked[t.Self().ID()] = true
// Generate the initial result set.
t.tab.mutex.Lock()
result = t.tab.closest(target, bucketSize, false)
t.tab.mutex.Unlock()
for {
// ask the alpha closest nodes that we haven't asked yet
for i := 0; i < len(result.entries) && pendingQueries < alpha; i++ {
n := result.entries[i]
if !asked[n.ID()] {
asked[n.ID()] = true
pendingQueries++
go t.lookupWorker(n, targetKey, reply)
}
}
if pendingQueries == 0 {
// we have asked all closest nodes, stop the search
break
}
select {
case nodes := <-reply:
for _, n := range nodes {
if n != nil && !seen[n.ID()] {
seen[n.ID()] = true
result.push(n, bucketSize)
}
}
case <-t.tab.closeReq:
return nil // shutdown, no need to continue.
}
pendingQueries--
}
return result.entries
}
func (t *UDPv4) lookupWorker(n *node, targetKey encPubkey, reply chan<- []*node) {
fails := t.db.FindFails(n.ID(), n.IP())
r, err := t.findnode(n.ID(), n.addr(), targetKey)
if err == errClosed {
// Avoid recording failures on shutdown.
reply <- nil
return
} else if len(r) == 0 {
fails++
t.db.UpdateFindFails(n.ID(), n.IP(), fails)
t.log.Trace("Findnode failed", "id", n.ID(), "failcount", fails, "err", err)
if fails >= maxFindnodeFailures {
t.log.Trace("Too many findnode failures, dropping", "id", n.ID(), "failcount", fails)
t.tab.delete(n)
}
} else if fails > 0 {
// Reset failure counter because it counts _consecutive_ failures.
t.db.UpdateFindFails(n.ID(), n.IP(), 0)
}
// Grab as many nodes as possible. Some of them might not be alive anymore, but we'll
// just remove those again during revalidation.
for _, n := range r {
t.tab.addSeenNode(n)
}
reply <- r
}
// Resolve searches for a specific node with the given ID and tries to get the most recent
// version of the node record for it. It returns n if the node could not be resolved.
func (t *UDPv4) Resolve(n *enode.Node) *enode.Node {
@ -498,6 +390,45 @@ func (t *UDPv4) makePing(toaddr *net.UDPAddr) *pingV4 {
}
}
// LookupPubkey finds the closest nodes to the given public key.
func (t *UDPv4) LookupPubkey(key *ecdsa.PublicKey) []*enode.Node {
if t.tab.len() == 0 {
// All nodes were dropped, refresh. The very first query will hit this
// case and run the bootstrapping logic.
<-t.tab.refresh()
}
return t.newLookup(t.closeCtx, encodePubkey(key)).run()
}
// RandomNodes is an iterator yielding nodes from a random walk of the DHT.
func (t *UDPv4) RandomNodes() enode.Iterator {
return newLookupIterator(t.closeCtx, t.newRandomLookup)
}
// lookupRandom implements transport.
func (t *UDPv4) lookupRandom() []*enode.Node {
return t.newRandomLookup(t.closeCtx).run()
}
// lookupSelf implements transport.
func (t *UDPv4) lookupSelf() []*enode.Node {
return t.newLookup(t.closeCtx, encodePubkey(&t.priv.PublicKey)).run()
}
func (t *UDPv4) newRandomLookup(ctx context.Context) *lookup {
var target encPubkey
crand.Read(target[:])
return t.newLookup(ctx, target)
}
func (t *UDPv4) newLookup(ctx context.Context, targetKey encPubkey) *lookup {
target := enode.ID(crypto.Keccak256Hash(targetKey[:]))
it := newLookup(ctx, t.tab, target, func(n *node) ([]*node, error) {
return t.findnode(n.ID(), n.addr(), targetKey)
})
return it
}
// findnode sends a findnode request to the given node and waits until
// the node has sent up to k neighbors.
func (t *UDPv4) findnode(toid enode.ID, toaddr *net.UDPAddr, target encPubkey) ([]*node, error) {
@ -575,7 +506,7 @@ func (t *UDPv4) pending(id enode.ID, ip net.IP, ptype byte, callback replyMatchF
select {
case t.addReplyMatcher <- p:
// loop will handle it
case <-t.closing:
case <-t.closeCtx.Done():
ch <- errClosed
}
return p
@ -589,7 +520,7 @@ func (t *UDPv4) handleReply(from enode.ID, fromIP net.IP, req packetV4) bool {
case t.gotreply <- reply{from, fromIP, req, matched}:
// loop will handle it
return <-matched
case <-t.closing:
case <-t.closeCtx.Done():
return false
}
}
@ -635,7 +566,7 @@ func (t *UDPv4) loop() {
resetTimeout()
select {
case <-t.closing:
case <-t.closeCtx.Done():
for el := plist.Front(); el != nil; el = el.Next() {
el.Value.(*replyMatcher).errc <- errClosed
}

286
p2p/enode/iter.go Normal file
View File

@ -0,0 +1,286 @@
// Copyright 2019 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 enode
import (
"sync"
"time"
)
// Iterator represents a sequence of nodes. The Next method moves to the next node in the
// sequence. It returns false when the sequence has ended or the iterator is closed. Close
// may be called concurrently with Next and Node, and interrupts Next if it is blocked.
type Iterator interface {
Next() bool // moves to next node
Node() *Node // returns current node
Close() // ends the iterator
}
// ReadNodes reads at most n nodes from the given iterator. The return value contains no
// duplicates and no nil values. To prevent looping indefinitely for small repeating node
// sequences, this function calls Next at most n times.
func ReadNodes(it Iterator, n int) []*Node {
seen := make(map[ID]*Node, n)
for i := 0; i < n && it.Next(); i++ {
// Remove duplicates, keeping the node with higher seq.
node := it.Node()
prevNode, ok := seen[node.ID()]
if ok && prevNode.Seq() > node.Seq() {
continue
}
seen[node.ID()] = node
}
result := make([]*Node, 0, len(seen))
for _, node := range seen {
result = append(result, node)
}
return result
}
// IterNodes makes an iterator which runs through the given nodes once.
func IterNodes(nodes []*Node) Iterator {
return &sliceIter{nodes: nodes, index: -1}
}
// CycleNodes makes an iterator which cycles through the given nodes indefinitely.
func CycleNodes(nodes []*Node) Iterator {
return &sliceIter{nodes: nodes, index: -1, cycle: true}
}
type sliceIter struct {
mu sync.Mutex
nodes []*Node
index int
cycle bool
}
func (it *sliceIter) Next() bool {
it.mu.Lock()
defer it.mu.Unlock()
if len(it.nodes) == 0 {
return false
}
it.index++
if it.index == len(it.nodes) {
if it.cycle {
it.index = 0
} else {
it.nodes = nil
return false
}
}
return true
}
func (it *sliceIter) Node() *Node {
if len(it.nodes) == 0 {
return nil
}
return it.nodes[it.index]
}
func (it *sliceIter) Close() {
it.mu.Lock()
defer it.mu.Unlock()
it.nodes = nil
}
// Filter wraps an iterator such that Next only returns nodes for which
// the 'check' function returns true.
func Filter(it Iterator, check func(*Node) bool) Iterator {
return &filterIter{it, check}
}
type filterIter struct {
Iterator
check func(*Node) bool
}
func (f *filterIter) Next() bool {
for f.Iterator.Next() {
if f.check(f.Node()) {
return true
}
}
return false
}
// FairMix aggregates multiple node iterators. The mixer itself is an iterator which ends
// only when Close is called. Source iterators added via AddSource are removed from the
// mix when they end.
//
// The distribution of nodes returned by Next is approximately fair, i.e. FairMix
// attempts to draw from all sources equally often. However, if a certain source is slow
// and doesn't return a node within the configured timeout, a node from any other source
// will be returned.
//
// It's safe to call AddSource and Close concurrently with Next.
type FairMix struct {
wg sync.WaitGroup
fromAny chan *Node
timeout time.Duration
cur *Node
mu sync.Mutex
closed chan struct{}
sources []*mixSource
last int
}
type mixSource struct {
it Iterator
next chan *Node
timeout time.Duration
}
// NewFairMix creates a mixer.
//
// The timeout specifies how long the mixer will wait for the next fairly-chosen source
// before giving up and taking a node from any other source. A good way to set the timeout
// is deciding how long you'd want to wait for a node on average. Passing a negative
// timeout makes the mixer completely fair.
func NewFairMix(timeout time.Duration) *FairMix {
m := &FairMix{
fromAny: make(chan *Node),
closed: make(chan struct{}),
timeout: timeout,
}
return m
}
// AddSource adds a source of nodes.
func (m *FairMix) AddSource(it Iterator) {
m.mu.Lock()
defer m.mu.Unlock()
if m.closed == nil {
return
}
m.wg.Add(1)
source := &mixSource{it, make(chan *Node), m.timeout}
m.sources = append(m.sources, source)
go m.runSource(m.closed, source)
}
// Close shuts down the mixer and all current sources.
// Calling this is required to release resources associated with the mixer.
func (m *FairMix) Close() {
m.mu.Lock()
defer m.mu.Unlock()
if m.closed == nil {
return
}
for _, s := range m.sources {
s.it.Close()
}
close(m.closed)
m.wg.Wait()
close(m.fromAny)
m.sources = nil
m.closed = nil
}
// Next returns a node from a random source.
func (m *FairMix) Next() bool {
m.cur = nil
var timeout <-chan time.Time
if m.timeout >= 0 {
timer := time.NewTimer(m.timeout)
timeout = timer.C
defer timer.Stop()
}
for {
source := m.pickSource()
if source == nil {
return m.nextFromAny()
}
select {
case n, ok := <-source.next:
if ok {
m.cur = n
source.timeout = m.timeout
return true
}
// This source has ended.
m.deleteSource(source)
case <-timeout:
source.timeout /= 2
return m.nextFromAny()
}
}
}
// Node returns the current node.
func (m *FairMix) Node() *Node {
return m.cur
}
// nextFromAny is used when there are no sources or when the 'fair' choice
// doesn't turn up a node quickly enough.
func (m *FairMix) nextFromAny() bool {
n, ok := <-m.fromAny
if ok {
m.cur = n
}
return ok
}
// pickSource chooses the next source to read from, cycling through them in order.
func (m *FairMix) pickSource() *mixSource {
m.mu.Lock()
defer m.mu.Unlock()
if len(m.sources) == 0 {
return nil
}
m.last = (m.last + 1) % len(m.sources)
return m.sources[m.last]
}
// deleteSource deletes a source.
func (m *FairMix) deleteSource(s *mixSource) {
m.mu.Lock()
defer m.mu.Unlock()
for i := range m.sources {
if m.sources[i] == s {
copy(m.sources[i:], m.sources[i+1:])
m.sources[len(m.sources)-1] = nil
m.sources = m.sources[:len(m.sources)-1]
break
}
}
}
// runSource reads a single source in a loop.
func (m *FairMix) runSource(closed chan struct{}, s *mixSource) {
defer m.wg.Done()
defer close(s.next)
for s.it.Next() {
n := s.it.Node()
select {
case s.next <- n:
case m.fromAny <- n:
case <-closed:
return
}
}
}

291
p2p/enode/iter_test.go Normal file
View File

@ -0,0 +1,291 @@
// Copyright 2019 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 enode
import (
"encoding/binary"
"runtime"
"sync/atomic"
"testing"
"time"
"github.com/ethereum/go-ethereum/p2p/enr"
)
func TestReadNodes(t *testing.T) {
nodes := ReadNodes(new(genIter), 10)
checkNodes(t, nodes, 10)
}
// This test checks that ReadNodes terminates when reading N nodes from an iterator
// which returns less than N nodes in an endless cycle.
func TestReadNodesCycle(t *testing.T) {
iter := &callCountIter{
Iterator: CycleNodes([]*Node{
testNode(0, 0),
testNode(1, 0),
testNode(2, 0),
}),
}
nodes := ReadNodes(iter, 10)
checkNodes(t, nodes, 3)
if iter.count != 10 {
t.Fatalf("%d calls to Next, want %d", iter.count, 100)
}
}
func TestFilterNodes(t *testing.T) {
nodes := make([]*Node, 100)
for i := range nodes {
nodes[i] = testNode(uint64(i), uint64(i))
}
it := Filter(IterNodes(nodes), func(n *Node) bool {
return n.Seq() >= 50
})
for i := 50; i < len(nodes); i++ {
if !it.Next() {
t.Fatal("Next returned false")
}
if it.Node() != nodes[i] {
t.Fatalf("iterator returned wrong node %v\nwant %v", it.Node(), nodes[i])
}
}
if it.Next() {
t.Fatal("Next returned true after underlying iterator has ended")
}
}
func checkNodes(t *testing.T, nodes []*Node, wantLen int) {
if len(nodes) != wantLen {
t.Errorf("slice has %d nodes, want %d", len(nodes), wantLen)
return
}
seen := make(map[ID]bool)
for i, e := range nodes {
if e == nil {
t.Errorf("nil node at index %d", i)
return
}
if seen[e.ID()] {
t.Errorf("slice has duplicate node %v", e.ID())
return
}
seen[e.ID()] = true
}
}
// This test checks fairness of FairMix in the happy case where all sources return nodes
// within the context's deadline.
func TestFairMix(t *testing.T) {
for i := 0; i < 500; i++ {
testMixerFairness(t)
}
}
func testMixerFairness(t *testing.T) {
mix := NewFairMix(1 * time.Second)
mix.AddSource(&genIter{index: 1})
mix.AddSource(&genIter{index: 2})
mix.AddSource(&genIter{index: 3})
defer mix.Close()
nodes := ReadNodes(mix, 500)
checkNodes(t, nodes, 500)
// Verify that the nodes slice contains an approximately equal number of nodes
// from each source.
d := idPrefixDistribution(nodes)
for _, count := range d {
if approxEqual(count, len(nodes)/3, 30) {
t.Fatalf("ID distribution is unfair: %v", d)
}
}
}
// This test checks that FairMix falls back to an alternative source when
// the 'fair' choice doesn't return a node within the timeout.
func TestFairMixNextFromAll(t *testing.T) {
mix := NewFairMix(1 * time.Millisecond)
mix.AddSource(&genIter{index: 1})
mix.AddSource(CycleNodes(nil))
defer mix.Close()
nodes := ReadNodes(mix, 500)
checkNodes(t, nodes, 500)
d := idPrefixDistribution(nodes)
if len(d) > 1 || d[1] != len(nodes) {
t.Fatalf("wrong ID distribution: %v", d)
}
}
// This test ensures FairMix works for Next with no sources.
func TestFairMixEmpty(t *testing.T) {
var (
mix = NewFairMix(1 * time.Second)
testN = testNode(1, 1)
ch = make(chan *Node)
)
defer mix.Close()
go func() {
mix.Next()
ch <- mix.Node()
}()
mix.AddSource(CycleNodes([]*Node{testN}))
if n := <-ch; n != testN {
t.Errorf("got wrong node: %v", n)
}
}
// This test checks closing a source while Next runs.
func TestFairMixRemoveSource(t *testing.T) {
mix := NewFairMix(1 * time.Second)
source := make(blockingIter)
mix.AddSource(source)
sig := make(chan *Node)
go func() {
<-sig
mix.Next()
sig <- mix.Node()
}()
sig <- nil
runtime.Gosched()
source.Close()
wantNode := testNode(0, 0)
mix.AddSource(CycleNodes([]*Node{wantNode}))
n := <-sig
if len(mix.sources) != 1 {
t.Fatalf("have %d sources, want one", len(mix.sources))
}
if n != wantNode {
t.Fatalf("mixer returned wrong node")
}
}
type blockingIter chan struct{}
func (it blockingIter) Next() bool {
<-it
return false
}
func (it blockingIter) Node() *Node {
return nil
}
func (it blockingIter) Close() {
close(it)
}
func TestFairMixClose(t *testing.T) {
for i := 0; i < 20 && !t.Failed(); i++ {
testMixerClose(t)
}
}
func testMixerClose(t *testing.T) {
mix := NewFairMix(-1)
mix.AddSource(CycleNodes(nil))
mix.AddSource(CycleNodes(nil))
done := make(chan struct{})
go func() {
defer close(done)
if mix.Next() {
t.Error("Next returned true")
}
}()
// This call is supposed to make it more likely that NextNode is
// actually executing by the time we call Close.
runtime.Gosched()
mix.Close()
select {
case <-done:
case <-time.After(3 * time.Second):
t.Fatal("Next didn't unblock on Close")
}
mix.Close() // shouldn't crash
}
func idPrefixDistribution(nodes []*Node) map[uint32]int {
d := make(map[uint32]int)
for _, node := range nodes {
id := node.ID()
d[binary.BigEndian.Uint32(id[:4])]++
}
return d
}
func approxEqual(x, y, ε int) bool {
if y > x {
x, y = y, x
}
return x-y > ε
}
// genIter creates fake nodes with numbered IDs based on 'index' and 'gen'
type genIter struct {
node *Node
index, gen uint32
}
func (s *genIter) Next() bool {
index := atomic.LoadUint32(&s.index)
if index == ^uint32(0) {
s.node = nil
return false
}
s.node = testNode(uint64(index)<<32|uint64(s.gen), 0)
s.gen++
return true
}
func (s *genIter) Node() *Node {
return s.node
}
func (s *genIter) Close() {
s.index = ^uint32(0)
}
func testNode(id, seq uint64) *Node {
var nodeID ID
binary.BigEndian.PutUint64(nodeID[:], id)
r := new(enr.Record)
r.SetSeq(seq)
return SignNull(r, nodeID)
}
// callCountIter counts calls to NextNode.
type callCountIter struct {
Iterator
count int
}
func (it *callCountIter) Next() bool {
it.count++
return it.Iterator.Next()
}

5
p2p/protocol.go
View File

@ -54,6 +54,11 @@ type Protocol struct {
// but returns nil, it is assumed that the protocol handshake is still running.
PeerInfo func(id enode.ID) interface{}
// DialCandidates, if non-nil, is a way to tell Server about protocol-specific nodes
// that should be dialed. The server continuously reads nodes from the iterator and
// attempts to create connections to them.
DialCandidates enode.Iterator
// Attributes contains protocol specific information for the node record.
Attributes []enr.Entry
}

35
p2p/server.go
View File

@ -45,6 +45,11 @@ import (
const (
defaultDialTimeout = 15 * time.Second
// This is the fairness knob for the discovery mixer. When looking for peers, we'll
// wait this long for a single source of candidates before moving on and trying other
// sources.
discmixTimeout = 5 * time.Second
// Connectivity defaults.
maxActiveDialTasks = 16
defaultMaxPendingPeers = 50
@ -167,16 +172,20 @@ type Server struct {
lock sync.Mutex // protects running
running bool
nodedb *enode.DB
localnode *enode.LocalNode
ntab discoverTable
listener net.Listener
ourHandshake *protoHandshake
DiscV5 *discv5.Network
loopWG sync.WaitGroup // loop, listenLoop
peerFeed event.Feed
log log.Logger
nodedb *enode.DB
localnode *enode.LocalNode
ntab *discover.UDPv4
DiscV5 *discv5.Network
discmix *enode.FairMix
staticNodeResolver nodeResolver
// Channels into the run loop.
quit chan struct{}
addstatic chan *enode.Node
@ -470,7 +479,7 @@ func (srv *Server) Start() (err error) {
}
dynPeers := srv.maxDialedConns()
dialer := newDialState(srv.localnode.ID(), srv.ntab, dynPeers, &srv.Config)
dialer := newDialState(srv.localnode.ID(), dynPeers, &srv.Config)
srv.loopWG.Add(1)
go srv.run(dialer)
return nil
@ -521,6 +530,18 @@ func (srv *Server) setupLocalNode() error {
}
func (srv *Server) setupDiscovery() error {
srv.discmix = enode.NewFairMix(discmixTimeout)
// Add protocol-specific discovery sources.
added := make(map[string]bool)
for _, proto := range srv.Protocols {
if proto.DialCandidates != nil && !added[proto.Name] {
srv.discmix.AddSource(proto.DialCandidates)
added[proto.Name] = true
}
}
// Don't listen on UDP endpoint if DHT is disabled.
if srv.NoDiscovery && !srv.DiscoveryV5 {
return nil
}
@ -562,7 +583,10 @@ func (srv *Server) setupDiscovery() error {
return err
}
srv.ntab = ntab
srv.discmix.AddSource(ntab.RandomNodes())
srv.staticNodeResolver = ntab
}
// Discovery V5
if srv.DiscoveryV5 {
var ntab *discv5.Network
@ -620,6 +644,7 @@ func (srv *Server) run(dialstate dialer) {
srv.log.Info("Started P2P networking", "self", srv.localnode.Node().URLv4())
defer srv.loopWG.Done()
defer srv.nodedb.Close()
defer srv.discmix.Close()
var (
peers = make(map[enode.ID]*Peer)

4
p2p/server_test.go
View File

@ -233,8 +233,8 @@ func TestServerTaskScheduling(t *testing.T) {
Config: Config{MaxPeers: 10},
localnode: enode.NewLocalNode(db, newkey()),
nodedb: db,
discmix: enode.NewFairMix(0),
quit: make(chan struct{}),
ntab: fakeTable{},
running: true,
log: log.New(),
}
@ -282,9 +282,9 @@ func TestServerManyTasks(t *testing.T) {
quit: make(chan struct{}),
localnode: enode.NewLocalNode(db, newkey()),
nodedb: db,
ntab: fakeTable{},
running: true,
log: log.New(),
discmix: enode.NewFairMix(0),
}
done = make(chan *testTask)
start, end = 0, 0