bsc/p2p/dial_test.go
Felix Lange 90caa2cabb
p2p: new dial scheduler (#20592)
* p2p: new dial scheduler

This change replaces the peer-to-peer dial scheduler with a new and
improved implementation. The new code is better than the previous
implementation in two key aspects:

- The time between discovery of a node and dialing that node is
  significantly lower in the new version. The old dialState kept
  a buffer of nodes and launched a task to refill it whenever the buffer
  became empty. This worked well with the discovery interface we used to
  have, but doesn't really work with the new iterator-based discovery
  API.

- Selection of static dial candidates (created by Server.AddPeer or
  through static-nodes.json) performs much better for large amounts of
  static peers. Connections to static nodes are now limited like dynanic
  dials and can no longer overstep MaxPeers or the dial ratio.

* p2p/simulations/adapters: adapt to new NodeDialer interface

* p2p: re-add check for self in checkDial

* p2p: remove peersetCh

* p2p: allow static dials when discovery is disabled

* p2p: add test for dialScheduler.removeStatic

* p2p: remove blank line

* p2p: fix documentation of maxDialPeers

* p2p: change "ok" to "added" in static node log

* p2p: improve dialTask docs

Also increase log level for "Can't resolve node"

* p2p: ensure dial resolver is truly nil without discovery

* p2p: add "looking for peers" log message

* p2p: clean up Server.run comments

* p2p: fix maxDialedConns for maxpeers < dialRatio

Always allocate at least one dial slot unless dialing is disabled using
NoDial or MaxPeers == 0. Most importantly, this fixes MaxPeers == 1 to
dedicate the sole slot to dialing instead of listening.

* p2p: fix RemovePeer to disconnect the peer again

Also make RemovePeer synchronous and add a test.

* p2p: remove "Connection set up" log message

* p2p: clean up connection logging

We previously logged outgoing connection failures up to three times.

- in SetupConn() as "Setting up connection failed addr=..."
- in setupConn() with an error-specific message and "id=... addr=..."
- in dial() as "Dial error task=..."

This commit ensures a single log message is emitted per failure and adds
"id=... addr=... conn=..." everywhere (id= omitted when the ID isn't
known yet).

Also avoid printing a log message when a static dial fails but can't be
resolved because discv4 is disabled. The light client hit this case all
the time, increasing the message count to four lines per failed
connection.

* p2p: document that RemovePeer blocks
2020-02-13 11:10:03 +01:00

673 lines
17 KiB
Go

// Copyright 2015 The go-ethereum Authors
// This file is part of the go-ethereum library.
//
// The go-ethereum library is free software: you can redistribute it and/or modify
// it under the terms of the GNU Lesser General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
//
// The go-ethereum library is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
// GNU Lesser General Public License for more details.
//
// You should have received a copy of the GNU Lesser General Public License
// along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>.
package p2p
import (
"context"
"errors"
"fmt"
"math/rand"
"net"
"reflect"
"sync"
"testing"
"time"
"github.com/ethereum/go-ethereum/common/mclock"
"github.com/ethereum/go-ethereum/internal/testlog"
"github.com/ethereum/go-ethereum/log"
"github.com/ethereum/go-ethereum/p2p/enode"
"github.com/ethereum/go-ethereum/p2p/netutil"
)
// This test checks that dynamic dials are launched from discovery results.
func TestDialSchedDynDial(t *testing.T) {
t.Parallel()
config := dialConfig{
maxActiveDials: 5,
maxDialPeers: 4,
}
runDialTest(t, config, []dialTestRound{
// 3 out of 4 peers are connected, leaving 2 dial slots.
// 9 nodes are discovered, but only 2 are dialed.
{
peersAdded: []*conn{
{flags: staticDialedConn, node: newNode(uintID(0x00), "")},
{flags: dynDialedConn, node: newNode(uintID(0x01), "")},
{flags: dynDialedConn, node: newNode(uintID(0x02), "")},
},
discovered: []*enode.Node{
newNode(uintID(0x00), "127.0.0.1:30303"), // not dialed because already connected as static peer
newNode(uintID(0x02), "127.0.0.1:30303"), // ...
newNode(uintID(0x03), "127.0.0.1:30303"),
newNode(uintID(0x04), "127.0.0.1:30303"),
newNode(uintID(0x05), "127.0.0.1:30303"), // not dialed because there are only two slots
newNode(uintID(0x06), "127.0.0.1:30303"), // ...
newNode(uintID(0x07), "127.0.0.1:30303"), // ...
newNode(uintID(0x08), "127.0.0.1:30303"), // ...
},
wantNewDials: []*enode.Node{
newNode(uintID(0x03), "127.0.0.1:30303"),
newNode(uintID(0x04), "127.0.0.1:30303"),
},
},
// One dial completes, freeing one dial slot.
{
failed: []enode.ID{
uintID(0x04),
},
wantNewDials: []*enode.Node{
newNode(uintID(0x05), "127.0.0.1:30303"),
},
},
// Dial to 0x03 completes, filling the last remaining peer slot.
{
succeeded: []enode.ID{
uintID(0x03),
},
failed: []enode.ID{
uintID(0x05),
},
discovered: []*enode.Node{
newNode(uintID(0x09), "127.0.0.1:30303"), // not dialed because there are no free slots
},
},
// 3 peers drop off, creating 6 dial slots. Check that 5 of those slots
// (i.e. up to maxActiveDialTasks) are used.
{
peersRemoved: []enode.ID{
uintID(0x00),
uintID(0x01),
uintID(0x02),
},
discovered: []*enode.Node{
newNode(uintID(0x0a), "127.0.0.1:30303"),
newNode(uintID(0x0b), "127.0.0.1:30303"),
newNode(uintID(0x0c), "127.0.0.1:30303"),
newNode(uintID(0x0d), "127.0.0.1:30303"),
newNode(uintID(0x0f), "127.0.0.1:30303"),
},
wantNewDials: []*enode.Node{
newNode(uintID(0x06), "127.0.0.1:30303"),
newNode(uintID(0x07), "127.0.0.1:30303"),
newNode(uintID(0x08), "127.0.0.1:30303"),
newNode(uintID(0x09), "127.0.0.1:30303"),
newNode(uintID(0x0a), "127.0.0.1:30303"),
},
},
})
}
// This test checks that candidates that do not match the netrestrict list are not dialed.
func TestDialSchedNetRestrict(t *testing.T) {
t.Parallel()
nodes := []*enode.Node{
newNode(uintID(0x01), "127.0.0.1:30303"),
newNode(uintID(0x02), "127.0.0.2:30303"),
newNode(uintID(0x03), "127.0.0.3:30303"),
newNode(uintID(0x04), "127.0.0.4:30303"),
newNode(uintID(0x05), "127.0.2.5:30303"),
newNode(uintID(0x06), "127.0.2.6:30303"),
newNode(uintID(0x07), "127.0.2.7:30303"),
newNode(uintID(0x08), "127.0.2.8:30303"),
}
config := dialConfig{
netRestrict: new(netutil.Netlist),
maxActiveDials: 10,
maxDialPeers: 10,
}
config.netRestrict.Add("127.0.2.0/24")
runDialTest(t, config, []dialTestRound{
{
discovered: nodes,
wantNewDials: nodes[4:8],
},
{
succeeded: []enode.ID{
nodes[4].ID(),
nodes[5].ID(),
nodes[6].ID(),
nodes[7].ID(),
},
},
})
}
// This test checks that static dials work and obey the limits.
func TestDialSchedStaticDial(t *testing.T) {
t.Parallel()
config := dialConfig{
maxActiveDials: 5,
maxDialPeers: 4,
}
runDialTest(t, config, []dialTestRound{
// Static dials are launched for the nodes that
// aren't yet connected.
{
peersAdded: []*conn{
{flags: dynDialedConn, node: newNode(uintID(0x01), "127.0.0.1:30303")},
{flags: dynDialedConn, node: newNode(uintID(0x02), "127.0.0.2:30303")},
},
update: func(d *dialScheduler) {
// These two are not dialed because they're already connected
// as dynamic peers.
d.addStatic(newNode(uintID(0x01), "127.0.0.1:30303"))
d.addStatic(newNode(uintID(0x02), "127.0.0.2:30303"))
// These nodes will be dialed:
d.addStatic(newNode(uintID(0x03), "127.0.0.3:30303"))
d.addStatic(newNode(uintID(0x04), "127.0.0.4:30303"))
d.addStatic(newNode(uintID(0x05), "127.0.0.5:30303"))
d.addStatic(newNode(uintID(0x06), "127.0.0.6:30303"))
d.addStatic(newNode(uintID(0x07), "127.0.0.7:30303"))
d.addStatic(newNode(uintID(0x08), "127.0.0.8:30303"))
d.addStatic(newNode(uintID(0x09), "127.0.0.9:30303"))
},
wantNewDials: []*enode.Node{
newNode(uintID(0x03), "127.0.0.3:30303"),
newNode(uintID(0x04), "127.0.0.4:30303"),
newNode(uintID(0x05), "127.0.0.5:30303"),
newNode(uintID(0x06), "127.0.0.6:30303"),
},
},
// Dial to 0x03 completes, filling a peer slot. One slot remains,
// two dials are launched to attempt to fill it.
{
succeeded: []enode.ID{
uintID(0x03),
},
failed: []enode.ID{
uintID(0x04),
uintID(0x05),
uintID(0x06),
},
wantResolves: map[enode.ID]*enode.Node{
uintID(0x04): nil,
uintID(0x05): nil,
uintID(0x06): nil,
},
wantNewDials: []*enode.Node{
newNode(uintID(0x08), "127.0.0.8:30303"),
newNode(uintID(0x09), "127.0.0.9:30303"),
},
},
// Peer 0x01 drops and 0x07 connects as inbound peer.
// Only 0x01 is dialed.
{
peersAdded: []*conn{
{flags: inboundConn, node: newNode(uintID(0x07), "127.0.0.7:30303")},
},
peersRemoved: []enode.ID{
uintID(0x01),
},
wantNewDials: []*enode.Node{
newNode(uintID(0x01), "127.0.0.1:30303"),
},
},
})
}
// This test checks that removing static nodes stops connecting to them.
func TestDialSchedRemoveStatic(t *testing.T) {
t.Parallel()
config := dialConfig{
maxActiveDials: 1,
maxDialPeers: 1,
}
runDialTest(t, config, []dialTestRound{
// Add static nodes.
{
update: func(d *dialScheduler) {
d.addStatic(newNode(uintID(0x01), "127.0.0.1:30303"))
d.addStatic(newNode(uintID(0x02), "127.0.0.2:30303"))
d.addStatic(newNode(uintID(0x03), "127.0.0.3:30303"))
},
wantNewDials: []*enode.Node{
newNode(uintID(0x01), "127.0.0.1:30303"),
},
},
// Dial to 0x01 fails.
{
failed: []enode.ID{
uintID(0x01),
},
wantResolves: map[enode.ID]*enode.Node{
uintID(0x01): nil,
},
wantNewDials: []*enode.Node{
newNode(uintID(0x02), "127.0.0.2:30303"),
},
},
// All static nodes are removed. 0x01 is in history, 0x02 is being
// dialed, 0x03 is in staticPool.
{
update: func(d *dialScheduler) {
d.removeStatic(newNode(uintID(0x01), "127.0.0.1:30303"))
d.removeStatic(newNode(uintID(0x02), "127.0.0.2:30303"))
d.removeStatic(newNode(uintID(0x03), "127.0.0.3:30303"))
},
failed: []enode.ID{
uintID(0x02),
},
wantResolves: map[enode.ID]*enode.Node{
uintID(0x02): nil,
},
},
// Since all static nodes are removed, they should not be dialed again.
{}, {}, {},
})
}
// This test checks that static dials are selected at random.
func TestDialSchedManyStaticNodes(t *testing.T) {
t.Parallel()
config := dialConfig{maxDialPeers: 2}
runDialTest(t, config, []dialTestRound{
{
peersAdded: []*conn{
{flags: dynDialedConn, node: newNode(uintID(0xFFFE), "")},
{flags: dynDialedConn, node: newNode(uintID(0xFFFF), "")},
},
update: func(d *dialScheduler) {
for id := uint16(0); id < 2000; id++ {
n := newNode(uintID(id), "127.0.0.1:30303")
d.addStatic(n)
}
},
},
{
peersRemoved: []enode.ID{
uintID(0xFFFE),
uintID(0xFFFF),
},
wantNewDials: []*enode.Node{
newNode(uintID(0x0085), "127.0.0.1:30303"),
newNode(uintID(0x02dc), "127.0.0.1:30303"),
newNode(uintID(0x0285), "127.0.0.1:30303"),
newNode(uintID(0x00cb), "127.0.0.1:30303"),
},
},
})
}
// This test checks that past dials are not retried for some time.
func TestDialSchedHistory(t *testing.T) {
t.Parallel()
config := dialConfig{
maxActiveDials: 3,
maxDialPeers: 3,
}
runDialTest(t, config, []dialTestRound{
{
update: func(d *dialScheduler) {
d.addStatic(newNode(uintID(0x01), "127.0.0.1:30303"))
d.addStatic(newNode(uintID(0x02), "127.0.0.2:30303"))
d.addStatic(newNode(uintID(0x03), "127.0.0.3:30303"))
},
wantNewDials: []*enode.Node{
newNode(uintID(0x01), "127.0.0.1:30303"),
newNode(uintID(0x02), "127.0.0.2:30303"),
newNode(uintID(0x03), "127.0.0.3:30303"),
},
},
// No new tasks are launched in this round because all static
// nodes are either connected or still being dialed.
{
succeeded: []enode.ID{
uintID(0x01),
uintID(0x02),
},
failed: []enode.ID{
uintID(0x03),
},
wantResolves: map[enode.ID]*enode.Node{
uintID(0x03): nil,
},
},
// Nothing happens in this round because we're waiting for
// node 0x3's history entry to expire.
{},
// The cache entry for node 0x03 has expired and is retried.
{
wantNewDials: []*enode.Node{
newNode(uintID(0x03), "127.0.0.3:30303"),
},
},
})
}
func TestDialSchedResolve(t *testing.T) {
t.Parallel()
config := dialConfig{
maxActiveDials: 1,
maxDialPeers: 1,
}
node := newNode(uintID(0x01), "")
resolved := newNode(uintID(0x01), "127.0.0.1:30303")
resolved2 := newNode(uintID(0x01), "127.0.0.55:30303")
runDialTest(t, config, []dialTestRound{
{
update: func(d *dialScheduler) {
d.addStatic(node)
},
wantResolves: map[enode.ID]*enode.Node{
uintID(0x01): resolved,
},
wantNewDials: []*enode.Node{
resolved,
},
},
{
failed: []enode.ID{
uintID(0x01),
},
wantResolves: map[enode.ID]*enode.Node{
uintID(0x01): resolved2,
},
wantNewDials: []*enode.Node{
resolved2,
},
},
})
}
// -------
// Code below here is the framework for the tests above.
type dialTestRound struct {
peersAdded []*conn
peersRemoved []enode.ID
update func(*dialScheduler) // called at beginning of round
discovered []*enode.Node // newly discovered nodes
succeeded []enode.ID // dials which succeed this round
failed []enode.ID // dials which fail this round
wantResolves map[enode.ID]*enode.Node
wantNewDials []*enode.Node // dials that should be launched in this round
}
func runDialTest(t *testing.T, config dialConfig, rounds []dialTestRound) {
var (
clock = new(mclock.Simulated)
iterator = newDialTestIterator()
dialer = newDialTestDialer()
resolver = new(dialTestResolver)
peers = make(map[enode.ID]*conn)
setupCh = make(chan *conn)
)
// Override config.
config.clock = clock
config.dialer = dialer
config.resolver = resolver
config.log = testlog.Logger(t, log.LvlTrace)
config.rand = rand.New(rand.NewSource(0x1111))
// Set up the dialer. The setup function below runs on the dialTask
// goroutine and adds the peer.
var dialsched *dialScheduler
setup := func(fd net.Conn, f connFlag, node *enode.Node) error {
conn := &conn{flags: f, node: node}
dialsched.peerAdded(conn)
setupCh <- conn
return nil
}
dialsched = newDialScheduler(config, iterator, setup)
defer dialsched.stop()
for i, round := range rounds {
// Apply peer set updates.
for _, c := range round.peersAdded {
if peers[c.node.ID()] != nil {
t.Fatalf("round %d: peer %v already connected", i, c.node.ID())
}
dialsched.peerAdded(c)
peers[c.node.ID()] = c
}
for _, id := range round.peersRemoved {
c := peers[id]
if c == nil {
t.Fatalf("round %d: can't remove non-existent peer %v", i, id)
}
dialsched.peerRemoved(c)
}
// Init round.
t.Logf("round %d (%d peers)", i, len(peers))
resolver.setAnswers(round.wantResolves)
if round.update != nil {
round.update(dialsched)
}
iterator.addNodes(round.discovered)
// Unblock dialTask goroutines.
if err := dialer.completeDials(round.succeeded, nil); err != nil {
t.Fatalf("round %d: %v", i, err)
}
for range round.succeeded {
conn := <-setupCh
peers[conn.node.ID()] = conn
}
if err := dialer.completeDials(round.failed, errors.New("oops")); err != nil {
t.Fatalf("round %d: %v", i, err)
}
// Wait for new tasks.
if err := dialer.waitForDials(round.wantNewDials); err != nil {
t.Fatalf("round %d: %v", i, err)
}
if !resolver.checkCalls() {
t.Fatalf("unexpected calls to Resolve: %v", resolver.calls)
}
clock.Run(16 * time.Second)
}
}
// dialTestIterator is the input iterator for dialer tests. This works a bit like a channel
// with infinite buffer: nodes are added to the buffer with addNodes, which unblocks Next
// and returns them from the iterator.
type dialTestIterator struct {
cur *enode.Node
mu sync.Mutex
buf []*enode.Node
cond *sync.Cond
closed bool
}
func newDialTestIterator() *dialTestIterator {
it := &dialTestIterator{}
it.cond = sync.NewCond(&it.mu)
return it
}
// addNodes adds nodes to the iterator buffer and unblocks Next.
func (it *dialTestIterator) addNodes(nodes []*enode.Node) {
it.mu.Lock()
defer it.mu.Unlock()
it.buf = append(it.buf, nodes...)
it.cond.Signal()
}
// Node returns the current node.
func (it *dialTestIterator) Node() *enode.Node {
return it.cur
}
// Next moves to the next node.
func (it *dialTestIterator) Next() bool {
it.mu.Lock()
defer it.mu.Unlock()
it.cur = nil
for len(it.buf) == 0 && !it.closed {
it.cond.Wait()
}
if it.closed {
return false
}
it.cur = it.buf[0]
copy(it.buf[:], it.buf[1:])
it.buf = it.buf[:len(it.buf)-1]
return true
}
// Close ends the iterator, unblocking Next.
func (it *dialTestIterator) Close() {
it.mu.Lock()
defer it.mu.Unlock()
it.closed = true
it.buf = nil
it.cond.Signal()
}
// dialTestDialer is the NodeDialer used by runDialTest.
type dialTestDialer struct {
init chan *dialTestReq
blocked map[enode.ID]*dialTestReq
}
type dialTestReq struct {
n *enode.Node
unblock chan error
}
func newDialTestDialer() *dialTestDialer {
return &dialTestDialer{
init: make(chan *dialTestReq),
blocked: make(map[enode.ID]*dialTestReq),
}
}
// Dial implements NodeDialer.
func (d *dialTestDialer) Dial(ctx context.Context, n *enode.Node) (net.Conn, error) {
req := &dialTestReq{n: n, unblock: make(chan error, 1)}
select {
case d.init <- req:
select {
case err := <-req.unblock:
pipe, _ := net.Pipe()
return pipe, err
case <-ctx.Done():
return nil, ctx.Err()
}
case <-ctx.Done():
return nil, ctx.Err()
}
}
// waitForDials waits for calls to Dial with the given nodes as argument.
// Those calls will be held blocking until completeDials is called with the same nodes.
func (d *dialTestDialer) waitForDials(nodes []*enode.Node) error {
waitset := make(map[enode.ID]*enode.Node)
for _, n := range nodes {
waitset[n.ID()] = n
}
timeout := time.NewTimer(1 * time.Second)
defer timeout.Stop()
for len(waitset) > 0 {
select {
case req := <-d.init:
want, ok := waitset[req.n.ID()]
if !ok {
return fmt.Errorf("attempt to dial unexpected node %v", req.n.ID())
}
if !reflect.DeepEqual(req.n, want) {
return fmt.Errorf("ENR of dialed node %v does not match test", req.n.ID())
}
delete(waitset, req.n.ID())
d.blocked[req.n.ID()] = req
case <-timeout.C:
var waitlist []enode.ID
for id := range waitset {
waitlist = append(waitlist, id)
}
return fmt.Errorf("timed out waiting for dials to %v", waitlist)
}
}
return d.checkUnexpectedDial()
}
func (d *dialTestDialer) checkUnexpectedDial() error {
select {
case req := <-d.init:
return fmt.Errorf("attempt to dial unexpected node %v", req.n.ID())
case <-time.After(150 * time.Millisecond):
return nil
}
}
// completeDials unblocks calls to Dial for the given nodes.
func (d *dialTestDialer) completeDials(ids []enode.ID, err error) error {
for _, id := range ids {
req := d.blocked[id]
if req == nil {
return fmt.Errorf("can't complete dial to %v", id)
}
req.unblock <- err
}
return nil
}
// dialTestResolver tracks calls to resolve.
type dialTestResolver struct {
mu sync.Mutex
calls []enode.ID
answers map[enode.ID]*enode.Node
}
func (t *dialTestResolver) setAnswers(m map[enode.ID]*enode.Node) {
t.mu.Lock()
defer t.mu.Unlock()
t.answers = m
t.calls = nil
}
func (t *dialTestResolver) checkCalls() bool {
t.mu.Lock()
defer t.mu.Unlock()
for _, id := range t.calls {
if _, ok := t.answers[id]; !ok {
return false
}
}
return true
}
func (t *dialTestResolver) Resolve(n *enode.Node) *enode.Node {
t.mu.Lock()
defer t.mu.Unlock()
t.calls = append(t.calls, n.ID())
return t.answers[n.ID()]
}