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connmgr: Refactor connection management into pkg

Browse source 
This commit introduces package connmgr which contains connection
management related functionality.

The following is an overview of the features the package provides:

- Maintain fixed number of outbound connections
- Optional connect-only mode
- Retry persistent connections with increasing back-off
- Source peers from DNS seeds
- Use Tor to resolve DNS
- Dynamic ban scores
- Test coverage

In addition, btcd has been refactored to make use of the new package by
extending the connection manager to work with the server to source and
maintain peer connections. The following is a broad overview of the
changes to integrate the package:

- Simplify peer state by removing pending, retry peers
- Refactor to remove retries which are now handled by connmgr
- Use callback to add addresses sourced from the  DNS seed

Finally the following connection-related things have been improved as a
part of this refactor:

- Fixes 100% cpu usage when network is down (#129)
- Fixes issues with max peers (#577)
- Simplify outbound peer connections management
This commit is contained in:
Javed Khan 2016-05-12 14:36:07 +05:30 committed by Dave Collins
parent 69fca4d9b1
commit bff2ba70fd
13 changed files with 1063 additions and 305 deletions
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5
config.go
View file

@ -20,6 +20,7 @@ import (
"strings"
"time"
"github.com/btcsuite/btcd/connmgr"
"github.com/btcsuite/btcd/database"
_ "github.com/btcsuite/btcd/database/ffldb"
"github.com/btcsuite/btcd/mempool"
@ -860,7 +861,7 @@ func loadConfig() (*config, []string, error) {
cfg.dial = proxy.Dial
if !cfg.NoOnion {
cfg.lookup = func(host string) ([]net.IP, error) {
return torLookupIP(host, cfg.Proxy)
return connmgr.TorLookupIP(host, cfg.Proxy)
}
}
}
@ -900,7 +901,7 @@ func loadConfig() (*config, []string, error) {
return proxy.Dial(a, b)
}
cfg.onionlookup = func(host string) ([]net.IP, error) {
return torLookupIP(host, cfg.OnionProxy)
return connmgr.TorLookupIP(host, cfg.OnionProxy)
}
} else {
cfg.oniondial = cfg.dial

39
connmgr/README.md Normal file
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@ -0,0 +1,39 @@
connmgr
=======
[![Build Status](http://img.shields.io/travis/btcsuite/btcd.svg)]
(https://travis-ci.org/btcsuite/btcd) [![ISC License]
(http://img.shields.io/badge/license-ISC-blue.svg)](http://copyfree.org)
[![GoDoc](https://img.shields.io/badge/godoc-reference-blue.svg)]
(http://godoc.org/github.com/btcsuite/btcd/connmgr)
Package connmgr implements a generic Bitcoin network connection manager.
## Overview
Connection Manager handles all the general connection concerns such as
maintaining a set number of outbound connections, sourcing peers, banning,
limiting max connections, tor lookup, etc.
The package provides a generic connection manager which is able to accept
connection requests from a source or a set of given addresses, dial them and
notify the caller on connections. The main intended use is to initialize a pool
of active connections and maintain them to remain connected to the P2P network.
In addition the connection manager provides the following utilities:
- Notifications on connections or disconnections
- Handle failures and retry new addresses from the source
- Connect only to specified addresses
- Permanent connections with increasing backoff retry timers
- Disconnect or Remove an established connection
## Installation and Updating
```bash
$ go get -u github.com/btcsuite/btcd/connmgr
```
## License
Package connmgr is licensed under the [copyfree](http://copyfree.org) ISC License.

371
connmgr/connmanager.go Normal file
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@ -0,0 +1,371 @@
// Copyright (c) 2016 The btcsuite developers
// Use of this source code is governed by an ISC
// license that can be found in the LICENSE file.
package connmgr
import (
"errors"
"fmt"
"net"
"sync"
"sync/atomic"
"time"
)
// maxFailedAttempts is the maximum number of successive failed connection
// attempts after which network failure is assumed and new connections will
// be delayed by the configured retry duration.
const maxFailedAttempts = 25
var (
//ErrDialNil is used to indicate that Dial cannot be nil in the configuration.
ErrDialNil = errors.New("Config: Dial cannot be nil")
// maxRetryDuration is the max duration of time retrying of a persistent
// connection is allowed to grow to. This is necessary since the retry
// logic uses a backoff mechanism which increases the interval base times
// the number of retries that have been done.
maxRetryDuration = time.Minute * 5
// defaultRetryDuration is the default duration of time for retrying
// persistent connections.
defaultRetryDuration = time.Second * 5
// defaultMaxOutbound is the default number of maximum outbound connections
// to maintain.
defaultMaxOutbound = uint32(8)
)
// DialFunc defines a function that dials a connection.
type DialFunc func(string, string) (net.Conn, error)
// AddressFunc defines a function that returns a network address to connect to.
type AddressFunc func() (string, error)
// ConnState represents the state of the requested connection.
type ConnState uint8
// ConnState can be either pending, established, disconnected or failed. When
// a new connection is requested, it is attempted and categorized as
// established or failed depending on the connection result. An established
// connection which was disconnected is categorized as disconnected.
const (
ConnPending ConnState = iota
ConnEstablished
ConnDisconnected
ConnFailed
)
// OnConnectionFunc is the signature of the callback function which is used to
// subscribe to new connections.
type OnConnectionFunc func(*ConnReq, net.Conn)
// OnDisconnectionFunc is the signature of the callback function which is used to
// notify disconnections.
type OnDisconnectionFunc func(*ConnReq)
// ConnReq is the connection request to a network address. If permanent, the
// connection will be retried on disconnection.
type ConnReq struct {
// The following variables must only be used atomically.
id uint64
Addr string
Permanent bool
conn net.Conn
state ConnState
stateMtx sync.RWMutex
retryCount uint32
}
// updateState updates the state of the connection request.
func (c *ConnReq) updateState(state ConnState) {
c.stateMtx.Lock()
c.state = state
c.stateMtx.Unlock()
}
// ID returns a unique identifier for the connection request.
func (c *ConnReq) ID() uint64 {
return atomic.LoadUint64(&c.id)
}
// State is the connection state of the requested connection.
func (c *ConnReq) State() ConnState {
c.stateMtx.RLock()
state := c.state
c.stateMtx.RUnlock()
return state
}
// String returns a human-readable string for the connection request.
func (c *ConnReq) String() string {
if c.Addr == "" {
return fmt.Sprintf("reqid %d", atomic.LoadUint64(&c.id))
}
return fmt.Sprintf("%s (reqid %d)", c.Addr, atomic.LoadUint64(&c.id))
}
// Config holds the configuration options related to the connection manager.
type Config struct {
// MaxOutbound is the maximum number of outbound network connections to
// maintain. Defaults to 8.
MaxOutbound uint32
// RetryDuration is the duration to wait before retrying connection
// requests. Defaults to 5s.
RetryDuration time.Duration
// OnConnection is a callback that is fired when a new connection is
// established.
OnConnection OnConnectionFunc
// OnDisconnection is a callback that is fired when a connection is
// disconnected.
OnDisconnection OnDisconnectionFunc
// GetNewAddress is a way to get an address to make a network connection
// to. If nil, no new connections will be made automatically.
GetNewAddress AddressFunc
// Dial connects to the address on the named network. It cannot be nil.
Dial DialFunc
}
// handleConnected is used to queue a successful connection.
type handleConnected struct {
c *ConnReq
conn net.Conn
}
// handleDisconnected is used to remove a connection.
type handleDisconnected struct {
id uint64
retry bool
}
// handleFailed is used to remove a pending connection.
type handleFailed struct {
c *ConnReq
err error
}
// ConnManager provides a manager to handle network connections.
type ConnManager struct {
// The following variables must only be used atomically.
connReqCount uint64
start int32
stop int32
cfg Config
wg sync.WaitGroup
failedAttempts uint64
requests chan interface{}
quit chan struct{}
}
// handleFailedConn handles a connection failed due to a disconnect or any
// other failure. If permanent, it retries the connection after the configured
// retry duration. Otherwise, if required, it makes a new connection request.
// After maxFailedConnectionAttempts new connections will be retried after the
// configured retry duration.
func (cm *ConnManager) handleFailedConn(c *ConnReq, retry bool) {
if atomic.LoadInt32(&cm.stop) != 0 {
return
}
if retry && c.Permanent {
c.retryCount++
d := time.Duration(c.retryCount) * cm.cfg.RetryDuration
if d > maxRetryDuration {
d = maxRetryDuration
}
log.Debugf("Retrying connection to %v in %v", c, d)
time.AfterFunc(d, func() {
cm.Connect(c)
})
} else if cm.cfg.GetNewAddress != nil {
cm.failedAttempts++
if cm.failedAttempts >= maxFailedAttempts {
log.Debugf("Max failed connection attempts reached: [%d] "+
"-- retrying connection in: %v", maxFailedAttempts,
cm.cfg.RetryDuration)
time.AfterFunc(cm.cfg.RetryDuration, func() {
cm.NewConnReq()
})
} else {
go cm.NewConnReq()
}
}
}
// connHandler handles all connection related requests. It must be run as a
// goroutine.
//
// The connection handler makes sure that we maintain a pool of active outbound
// connections so that we remain connected to the network. Connection requests
// are processed and mapped by their assigned ids.
func (cm *ConnManager) connHandler() {
conns := make(map[uint64]*ConnReq, cm.cfg.MaxOutbound)
out:
for {
select {
case req := <-cm.requests:
switch msg := req.(type) {
case handleConnected:
connReq := msg.c
connReq.updateState(ConnEstablished)
connReq.conn = msg.conn
conns[connReq.id] = connReq
log.Debugf("Connected to %v", connReq)
connReq.retryCount = 0
cm.failedAttempts = 0
if cm.cfg.OnConnection != nil {
go cm.cfg.OnConnection(connReq, msg.conn)
}
case handleDisconnected:
if connReq, ok := conns[msg.id]; ok {
connReq.updateState(ConnDisconnected)
if connReq.conn != nil {
connReq.conn.Close()
}
log.Debugf("Disconnected from %v", connReq)
delete(conns, msg.id)
if cm.cfg.OnDisconnection != nil {
go cm.cfg.OnDisconnection(connReq)
}
cm.handleFailedConn(connReq, msg.retry)
} else {
log.Errorf("Unknown connection: %d", msg.id)
}
case handleFailed:
connReq := msg.c
connReq.updateState(ConnFailed)
log.Debugf("Failed to connect to %v: %v", connReq, msg.err)
cm.handleFailedConn(connReq, true)
}
case <-cm.quit:
break out
}
}
cm.wg.Done()
log.Trace("Connection handler done")
}
// NewConnReq creates a new connection request and connects to the
// corresponding address.
func (cm *ConnManager) NewConnReq() {
if atomic.LoadInt32(&cm.stop) != 0 {
return
}
if cm.cfg.GetNewAddress == nil {
return
}
c := &ConnReq{}
atomic.StoreUint64(&c.id, atomic.AddUint64(&cm.connReqCount, 1))
addr, err := cm.cfg.GetNewAddress()
if err != nil {
cm.requests <- handleFailed{c, err}
return
}
c.Addr = addr
cm.Connect(c)
}
// Connect assigns an id and dials a connection to the address of the
// connection request.
func (cm *ConnManager) Connect(c *ConnReq) {
if atomic.LoadInt32(&cm.stop) != 0 {
return
}
if atomic.LoadUint64(&c.id) == 0 {
atomic.StoreUint64(&c.id, atomic.AddUint64(&cm.connReqCount, 1))
}
log.Debugf("Attempting to connect to %v", c)
conn, err := cm.cfg.Dial("tcp", c.Addr)
if err != nil {
cm.requests <- handleFailed{c, err}
} else {
cm.requests <- handleConnected{c, conn}
}
}
// Disconnect disconnects the connection corresponding to the given connection
// id. If permanent, the connection will be retried with an increasing backoff
// duration.
func (cm *ConnManager) Disconnect(id uint64) {
if atomic.LoadInt32(&cm.stop) != 0 {
return
}
cm.requests <- handleDisconnected{id, true}
}
// Remove removes the connection corresponding to the given connection
// id from known connections.
func (cm *ConnManager) Remove(id uint64) {
if atomic.LoadInt32(&cm.stop) != 0 {
return
}
cm.requests <- handleDisconnected{id, false}
}
// Start launches the connection manager and begins connecting to the network.
func (cm *ConnManager) Start() {
// Already started?
if atomic.AddInt32(&cm.start, 1) != 1 {
return
}
log.Trace("Connection manager started")
cm.wg.Add(1)
go cm.connHandler()
for i := atomic.LoadUint64(&cm.connReqCount); i < uint64(cm.cfg.MaxOutbound); i++ {
go cm.NewConnReq()
}
}
// Wait blocks until the connection manager halts gracefully.
func (cm *ConnManager) Wait() {
cm.wg.Wait()
}
// Stop gracefully shuts down the connection manager.
func (cm *ConnManager) Stop() {
if atomic.AddInt32(&cm.stop, 1) != 1 {
log.Warnf("Connection manager already stopped")
return
}
close(cm.quit)
log.Trace("Connection manager stopped")
}
// New returns a new connection manager.
// Use Start to start connecting to the network.
func New(cfg *Config) (*ConnManager, error) {
if cfg.Dial == nil {
return nil, ErrDialNil
}
// Default to sane values
if cfg.RetryDuration <= 0 {
cfg.RetryDuration = defaultRetryDuration
}
if cfg.MaxOutbound == 0 {
cfg.MaxOutbound = defaultMaxOutbound
}
cm := ConnManager{
cfg: *cfg, // Copy so caller can't mutate
requests: make(chan interface{}),
quit: make(chan struct{}),
}
return &cm, nil
}

389
connmgr/connmanager_test.go Normal file
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@ -0,0 +1,389 @@
// Copyright (c) 2016 The btcsuite developers
// Use of this source code is governed by an ISC
// license that can be found in the LICENSE file.
package connmgr
import (
"bytes"
"errors"
"io"
"net"
"sync/atomic"
"testing"
"time"
"github.com/btcsuite/btclog"
)
func init() {
// Override the max retry duration when running tests.
maxRetryDuration = 2 * time.Millisecond
}
// mockAddr mocks a network address
type mockAddr struct {
net, address string
}
func (m mockAddr) Network() string { return m.net }
func (m mockAddr) String() string { return m.address }
// mockConn mocks a network connection by implementing the net.Conn interface.
type mockConn struct {
io.Reader
io.Writer
io.Closer
// local network, address for the connection.
lnet, laddr string
// remote network, address for the connection.
rnet, raddr string
}
// LocalAddr returns the local address for the connection.
func (c mockConn) LocalAddr() net.Addr {
return &mockAddr{c.lnet, c.laddr}
}
// RemoteAddr returns the remote address for the connection.
func (c mockConn) RemoteAddr() net.Addr {
return &mockAddr{c.rnet, c.raddr}
}
// Close handles closing the connection.
func (c mockConn) Close() error {
return nil
}
func (c mockConn) SetDeadline(t time.Time) error { return nil }
func (c mockConn) SetReadDeadline(t time.Time) error { return nil }
func (c mockConn) SetWriteDeadline(t time.Time) error { return nil }
// mockDialer mocks the net.Dial interface by returning a mock connection to
// the given address.
func mockDialer(network, address string) (net.Conn, error) {
r, w := io.Pipe()
c := &mockConn{raddr: address}
c.Reader = r
c.Writer = w
return c, nil
}
// TestNewConfig tests that new ConnManager config is validated as expected.
func TestNewConfig(t *testing.T) {
_, err := New(&Config{})
if err == nil {
t.Fatalf("New expected error: 'Dial can't be nil', got nil")
}
_, err = New(&Config{
Dial: mockDialer,
})
if err != nil {
t.Fatalf("New unexpected error: %v", err)
}
}
// TestUseLogger tests that a logger can be passed to UseLogger
func TestUseLogger(t *testing.T) {
l, err := btclog.NewLoggerFromWriter(bytes.NewBuffer(nil), btclog.InfoLvl)
if err != nil {
t.Fatal(err)
}
UseLogger(l)
}
// TestStartStop tests that the connection manager starts and stops as
// expected.
func TestStartStop(t *testing.T) {
connected := make(chan *ConnReq)
disconnected := make(chan *ConnReq)
cmgr, err := New(&Config{
MaxOutbound: 1,
GetNewAddress: func() (string, error) { return "127.0.0.1:18555", nil },
Dial: mockDialer,
OnConnection: func(c *ConnReq, conn net.Conn) {
connected <- c
},
OnDisconnection: func(c *ConnReq) {
disconnected <- c
},
})
if err != nil {
t.Fatalf("New error: %v", err)
}
cmgr.Start()
gotConnReq := <-connected
cmgr.Stop()
// already stopped
cmgr.Stop()
// ignored
cr := &ConnReq{Addr: "127.0.0.1:18555", Permanent: true}
cmgr.Connect(cr)
if cr.ID() != 0 {
t.Fatalf("start/stop: got id: %v, want: 0", cr.ID())
}
cmgr.Disconnect(gotConnReq.ID())
cmgr.Remove(gotConnReq.ID())
select {
case <-disconnected:
t.Fatalf("start/stop: unexpected disconnection")
case <-time.Tick(10 * time.Millisecond):
break
}
}
// TestConnectMode tests that the connection manager works in the connect mode.
//
// In connect mode, automatic connections are disabled, so we test that
// requests using Connect are handled and that no other connections are made.
func TestConnectMode(t *testing.T) {
connected := make(chan *ConnReq)
cmgr, err := New(&Config{
MaxOutbound: 2,
Dial: mockDialer,
OnConnection: func(c *ConnReq, conn net.Conn) {
connected <- c
},
})
if err != nil {
t.Fatalf("New error: %v", err)
}
cr := &ConnReq{Addr: "127.0.0.1:18555", Permanent: true}
cmgr.Start()
cmgr.Connect(cr)
gotConnReq := <-connected
wantID := cr.ID()
gotID := gotConnReq.ID()
if gotID != wantID {
t.Fatalf("connect mode: %v - want ID %v, got ID %v", cr.Addr, wantID, gotID)
}
gotState := cr.State()
wantState := ConnEstablished
if gotState != wantState {
t.Fatalf("connect mode: %v - want state %v, got state %v", cr.Addr, wantState, gotState)
}
select {
case c := <-connected:
t.Fatalf("connect mode: got unexpected connection - %v", c.Addr)
case <-time.After(time.Millisecond):
break
}
cmgr.Stop()
}
// TestMaxOutbound tests the maximum number of outbound connections.
//
// We wait until all connections are established, then test they there are the
// only connections made.
func TestMaxOutbound(t *testing.T) {
maxOutbound := uint32(10)
connected := make(chan *ConnReq)
cmgr, err := New(&Config{
MaxOutbound: maxOutbound,
Dial: mockDialer,
GetNewAddress: func() (string, error) { return "127.0.0.1:18555", nil },
OnConnection: func(c *ConnReq, conn net.Conn) {
connected <- c
},
})
if err != nil {
t.Fatalf("New error: %v", err)
}
cmgr.Start()
for i := uint32(0); i < maxOutbound; i++ {
<-connected
}
select {
case c := <-connected:
t.Fatalf("max outbound: got unexpected connection - %v", c.Addr)
case <-time.After(time.Millisecond):
break
}
cmgr.Stop()
}
// TestRetryPermanent tests that permanent connection requests are retried.
//
// We make a permanent connection request using Connect, disconnect it using
// Disconnect and we wait for it to be connected back.
func TestRetryPermanent(t *testing.T) {
connected := make(chan *ConnReq)
disconnected := make(chan *ConnReq)
cmgr, err := New(&Config{
RetryDuration: time.Millisecond,
MaxOutbound: 1,
Dial: mockDialer,
OnConnection: func(c *ConnReq, conn net.Conn) {
connected <- c
},
OnDisconnection: func(c *ConnReq) {
disconnected <- c
},
})
if err != nil {
t.Fatalf("New error: %v", err)
}
cr := &ConnReq{Addr: "127.0.0.1:18555", Permanent: true}
go cmgr.Connect(cr)
cmgr.Start()
gotConnReq := <-connected
wantID := cr.ID()
gotID := gotConnReq.ID()
if gotID != wantID {
t.Fatalf("retry: %v - want ID %v, got ID %v", cr.Addr, wantID, gotID)
}
gotState := cr.State()
wantState := ConnEstablished
if gotState != wantState {
t.Fatalf("retry: %v - want state %v, got state %v", cr.Addr, wantState, gotState)
}
cmgr.Disconnect(cr.ID())
gotConnReq = <-disconnected
wantID = cr.ID()
gotID = gotConnReq.ID()
if gotID != wantID {
t.Fatalf("retry: %v - want ID %v, got ID %v", cr.Addr, wantID, gotID)
}
gotState = cr.State()
wantState = ConnDisconnected
if gotState != wantState {
t.Fatalf("retry: %v - want state %v, got state %v", cr.Addr, wantState, gotState)
}
gotConnReq = <-connected
wantID = cr.ID()
gotID = gotConnReq.ID()
if gotID != wantID {
t.Fatalf("retry: %v - want ID %v, got ID %v", cr.Addr, wantID, gotID)
}
gotState = cr.State()
wantState = ConnEstablished
if gotState != wantState {
t.Fatalf("retry: %v - want state %v, got state %v", cr.Addr, wantState, gotState)
}
cmgr.Remove(cr.ID())
gotConnReq = <-disconnected
wantID = cr.ID()
gotID = gotConnReq.ID()
if gotID != wantID {
t.Fatalf("retry: %v - want ID %v, got ID %v", cr.Addr, wantID, gotID)
}
gotState = cr.State()
wantState = ConnDisconnected
if gotState != wantState {
t.Fatalf("retry: %v - want state %v, got state %v", cr.Addr, wantState, gotState)
}
cmgr.Stop()
}
// TestMaxRetryDuration tests the maximum retry duration.
//
// We have a timed dialer which initially returns err but after RetryDuration
// hits maxRetryDuration returns a mock conn.
func TestMaxRetryDuration(t *testing.T) {
networkUp := make(chan struct{})
time.AfterFunc(5*time.Millisecond, func() {
close(networkUp)
})
timedDialer := func(network, address string) (net.Conn, error) {
select {
case <-networkUp:
return mockDialer(network, address)
default:
return nil, errors.New("network down")
}
}
connected := make(chan *ConnReq)
cmgr, err := New(&Config{
RetryDuration: time.Millisecond,
MaxOutbound: 1,
Dial: timedDialer,
OnConnection: func(c *ConnReq, conn net.Conn) {
connected <- c
},
})
if err != nil {
t.Fatalf("New error: %v", err)
}
cr := &ConnReq{Addr: "127.0.0.1:18555", Permanent: true}
go cmgr.Connect(cr)
cmgr.Start()
// retry in 1ms
// retry in 2ms - max retry duration reached
// retry in 2ms - timedDialer returns mockDial
select {
case <-connected:
case <-time.Tick(100 * time.Millisecond):
t.Fatalf("max retry duration: connection timeout")
}
}
// TestNetworkFailure tests that the connection manager handles a network
// failure gracefully.
func TestNetworkFailure(t *testing.T) {
var dials uint32
errDialer := func(network, address string) (net.Conn, error) {
atomic.AddUint32(&dials, 1)
return nil, errors.New("network down")
}
cmgr, err := New(&Config{
MaxOutbound: 5,
RetryDuration: 5 * time.Millisecond,
Dial: errDialer,
GetNewAddress: func() (string, error) { return "127.0.0.1:18555", nil },
OnConnection: func(c *ConnReq, conn net.Conn) {
t.Fatalf("network failure: got unexpected connection - %v", c.Addr)
},
})
if err != nil {
t.Fatalf("New error: %v", err)
}
cmgr.Start()
time.AfterFunc(10*time.Millisecond, cmgr.Stop)
cmgr.Wait()
wantMaxDials := uint32(75)
if atomic.LoadUint32(&dials) > wantMaxDials {
t.Fatalf("network failure: unexpected number of dials - got %v, want < %v",
atomic.LoadUint32(&dials), wantMaxDials)
}
}
// TestStopFailed tests that failed connections are ignored after connmgr is
// stopped.
//
// We have a dailer which sets the stop flag on the conn manager and returns an
// err so that the handler assumes that the conn manager is stopped and ignores
// the failure.
func TestStopFailed(t *testing.T) {
done := make(chan struct{}, 1)
waitDialer := func(network, address string) (net.Conn, error) {
done <- struct{}{}
time.Sleep(time.Millisecond)
return nil, errors.New("network down")
}
cmgr, err := New(&Config{
Dial: waitDialer,
})
if err != nil {
t.Fatalf("New error: %v", err)
}
cmgr.Start()
go func() {
<-done
atomic.StoreInt32(&cmgr.stop, 1)
time.Sleep(2 * time.Millisecond)
atomic.StoreInt32(&cmgr.stop, 0)
cmgr.Stop()
}()
cr := &ConnReq{Addr: "127.0.0.1:18555", Permanent: true}
go cmgr.Connect(cr)
cmgr.Wait()
}

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connmgr/doc.go Normal file
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@ -0,0 +1,14 @@
// Copyright (c) 2016 The btcsuite developers
// Use of this source code is governed by an ISC
// license that can be found in the LICENSE file.
/*
Package connmgr implements a generic Bitcoin network connection manager.
Connection Manager Overview
Connection Manager handles all the general connection concerns such as
maintaining a set number of outbound connections, sourcing peers, banning,
limiting max connections, tor lookup, etc.
*/
package connmgr

22
dynamicbanscore.go → connmgr/dynamicbanscore.go
View file

@ -2,7 +2,7 @@
// Use of this source code is governed by an ISC
// license that can be found in the LICENSE file.
package main
package connmgr
import (
"fmt"
@ -48,7 +48,7 @@ func decayFactor(t int64) float64 {
return math.Exp(-1.0 * float64(t) * lambda)
}
// dynamicBanScore provides dynamic ban scores consisting of a persistent and a
// DynamicBanScore provides dynamic ban scores consisting of a persistent and a
// decaying component. The persistent score could be utilized to create simple
// additive banning policies similar to those found in other bitcoin node
// implementations.
@ -56,11 +56,11 @@ func decayFactor(t int64) float64 {
// The decaying score enables the creation of evasive logic which handles
// misbehaving peers (especially application layer DoS attacks) gracefully
// by disconnecting and banning peers attempting various kinds of flooding.
// dynamicBanScore allows these two approaches to be used in tandem.
// DynamicBanScore allows these two approaches to be used in tandem.
//
// Zero value: Values of type dynamicBanScore are immediately ready for use upon
// Zero value: Values of type DynamicBanScore are immediately ready for use upon
// declaration.
type dynamicBanScore struct {
type DynamicBanScore struct {
lastUnix int64
transient float64
persistent uint32
@ -68,7 +68,7 @@ type dynamicBanScore struct {
}
// String returns the ban score as a human-readable string.
func (s *dynamicBanScore) String() string {
func (s *DynamicBanScore) String() string {
s.Lock()
r := fmt.Sprintf("persistent %v + transient %v at %v = %v as of now",
s.persistent, s.transient, s.lastUnix, s.Int())
@ -80,7 +80,7 @@ func (s *dynamicBanScore) String() string {
// scores.
//
// This function is safe for concurrent access.
func (s *dynamicBanScore) Int() uint32 {
func (s *DynamicBanScore) Int() uint32 {
s.Lock()
r := s.int(time.Now())
s.Unlock()
@ -91,7 +91,7 @@ func (s *dynamicBanScore) Int() uint32 {
// passed as parameters. The resulting score is returned.
//
// This function is safe for concurrent access.
func (s *dynamicBanScore) Increase(persistent, transient uint32) uint32 {
func (s *DynamicBanScore) Increase(persistent, transient uint32) uint32 {
s.Lock()
r := s.increase(persistent, transient, time.Now())
s.Unlock()
@ -101,7 +101,7 @@ func (s *dynamicBanScore) Increase(persistent, transient uint32) uint32 {
// Reset set both persistent and decaying scores to zero.
//
// This function is safe for concurrent access.
func (s *dynamicBanScore) Reset() {
func (s *DynamicBanScore) Reset() {
s.Lock()
s.persistent = 0
s.transient = 0
@ -114,7 +114,7 @@ func (s *dynamicBanScore) Reset() {
//
// This function is not safe for concurrent access. It is intended to be used
// internally and during testing.
func (s *dynamicBanScore) int(t time.Time) uint32 {
func (s *DynamicBanScore) int(t time.Time) uint32 {
dt := t.Unix() - s.lastUnix
if s.transient < 1 || dt < 0 || Lifetime < dt {
return s.persistent
@ -128,7 +128,7 @@ func (s *dynamicBanScore) int(t time.Time) uint32 {
// resulting score is returned.
//
// This function is not safe for concurrent access.
func (s *dynamicBanScore) increase(persistent, transient uint32, t time.Time) uint32 {
func (s *DynamicBanScore) increase(persistent, transient uint32, t time.Time) uint32 {
s.persistent += persistent
tu := t.Unix()
dt := tu - s.lastUnix

14
dynamicbanscore_test.go → connmgr/dynamicbanscore_test.go
View file

@ -2,7 +2,7 @@
// Use of this source code is governed by an ISC
// license that can be found in the LICENSE file.
package main
package connmgr
import (
"math"
@ -11,9 +11,9 @@ import (
)
// TestDynamicBanScoreDecay tests the exponential decay implemented in
// dynamicBanScore.
// DynamicBanScore.
func TestDynamicBanScoreDecay(t *testing.T) {
var bs dynamicBanScore
var bs DynamicBanScore
base := time.Now()
r := bs.increase(100, 50, base)
@ -32,10 +32,10 @@ func TestDynamicBanScoreDecay(t *testing.T) {
}
}
// TestDynamicBanScoreLifetime tests that dynamicBanScore properly yields zero
// TestDynamicBanScoreLifetime tests that DynamicBanScore properly yields zero
// once the maximum age is reached.
func TestDynamicBanScoreLifetime(t *testing.T) {
var bs dynamicBanScore
var bs DynamicBanScore
base := time.Now()
r := bs.increase(0, math.MaxUint32, base)
@ -49,10 +49,10 @@ func TestDynamicBanScoreLifetime(t *testing.T) {
}
}
// TestDynamicBanScore tests exported functions of dynamicBanScore. Exponential
// TestDynamicBanScore tests exported functions of DynamicBanScore. Exponential
// decay or other time based behavior is tested by other functions.
func TestDynamicBanScoreReset(t *testing.T) {
var bs dynamicBanScore
var bs DynamicBanScore
if bs.Int() != 0 {
t.Errorf("Initial state is not zero.")
}

30
connmgr/log.go Normal file
View file

@ -0,0 +1,30 @@
// Copyright (c) 2016 The btcsuite developers
// Use of this source code is governed by an ISC
// license that can be found in the LICENSE file.
package connmgr
import "github.com/btcsuite/btclog"
// log is a logger that is initialized with no output filters. This
// means the package will not perform any logging by default until the caller
// requests it.
var log btclog.Logger
// The default amount of logging is none.
func init() {
DisableLog()
}
// DisableLog disables all library log output. Logging output is disabled
// by default until either UseLogger or SetLogWriter are called.
func DisableLog() {
log = btclog.Disabled
}
// UseLogger uses a specified Logger to output package logging info.
// This should be used in preference to SetLogWriter if the caller is also
// using btclog.
func UseLogger(logger btclog.Logger) {
log = logger
}

66
connmgr/seed.go Normal file
View file

@ -0,0 +1,66 @@
// Copyright (c) 2016 The btcsuite developers
// Use of this source code is governed by an ISC
// license that can be found in the LICENSE file.
package connmgr
import (
mrand "math/rand"
"net"
"strconv"
"time"
"github.com/btcsuite/btcd/chaincfg"
"github.com/btcsuite/btcd/wire"
)
const (
// These constants are used by the DNS seed code to pick a random last
// seen time.
secondsIn3Days int32 = 24 * 60 * 60 * 3
secondsIn4Days int32 = 24 * 60 * 60 * 4
)
// OnSeed is the signature of the callback function which is invoked when DNS
// seeding is succesfull.
type OnSeed func(addrs []*wire.NetAddress)
// LookupFunc is the signature of the DNS lookup function.
type LookupFunc func(string) ([]net.IP, error)
// SeedFromDNS uses DNS seeding to populate the address manager with peers.
func SeedFromDNS(chainParams *chaincfg.Params, lookupFn LookupFunc, seedFn OnSeed) {
for _, seeder := range chainParams.DNSSeeds {
go func(seeder string) {
randSource := mrand.New(mrand.NewSource(time.Now().UnixNano()))
seedpeers, err := lookupFn(seeder)
if err != nil {
log.Infof("DNS discovery failed on seed %s: %v", seeder, err)
return
}
numPeers := len(seedpeers)
log.Infof("%d addresses found from DNS seed %s", numPeers, seeder)
if numPeers == 0 {
return
}
addresses := make([]*wire.NetAddress, len(seedpeers))
// if this errors then we have *real* problems
intPort, _ := strconv.Atoi(chainParams.DefaultPort)
for i, peer := range seedpeers {
addresses[i] = new(wire.NetAddress)
addresses[i].SetAddress(peer, uint16(intPort))
// bitcoind seeds with addresses from
// a time randomly selected between 3
// and 7 days ago.
addresses[i].Timestamp = time.Now().Add(-1 *
time.Second * time.Duration(secondsIn3Days+
randSource.Int31n(secondsIn4Days)))
}
seedFn(addresses)
}(seeder)
}
}

20
discovery.go → connmgr/tor.go
View file

@ -1,8 +1,8 @@
// Copyright (c) 2013-2014 The btcsuite developers
// Copyright (c) 2013-2016 The btcsuite developers
// Use of this source code is governed by an ISC
// license that can be found in the LICENSE file.
package main
package connmgr
import (
"encoding/binary"
@ -48,10 +48,10 @@ var (
}
)
// torLookupIP uses Tor to resolve DNS via the SOCKS extension they provide for
// TorLookupIP uses Tor to resolve DNS via the SOCKS extension they provide for
// resolution over the Tor network. Tor itself doesn't support ipv6 so this
// doesn't either.
func torLookupIP(host, proxy string) ([]net.IP, error) {
func TorLookupIP(host, proxy string) ([]net.IP, error) {
conn, err := net.Dial("tcp", proxy)
if err != nil {
return nil, err
@ -130,15 +130,3 @@ func torLookupIP(host, proxy string) ([]net.IP, error) {
return addr, nil
}
// dnsDiscover looks up the list of peers resolved by DNS for all hosts in
// seeders. If proxy is not "" then it is used as a tor proxy for the
// resolution.
func dnsDiscover(seeder string) ([]net.IP, error) {
peers, err := btcdLookup(seeder)
if err != nil {
return nil, err
}
return peers, nil
}

2
docs/README.md
View file

@ -259,3 +259,5 @@ information.
* [chainhash](https://github.com/btcsuite/btcd/tree/master/chaincfg/chainhash) -
Provides a generic hash type and associated functions that allows the
specific hash algorithm to be abstracted.
* [connmgr](https://github.com/btcsuite/btcd/tree/master/connmgr) -
Package connmgr implements a generic Bitcoin network connection manager.

7
log.go
View file

@ -11,6 +11,7 @@ import (
"github.com/btcsuite/btcd/addrmgr"
"github.com/btcsuite/btcd/blockchain"
"github.com/btcsuite/btcd/blockchain/indexers"
"github.com/btcsuite/btcd/connmgr"
"github.com/btcsuite/btcd/database"
"github.com/btcsuite/btcd/mempool"
"github.com/btcsuite/btcd/peer"
@ -33,6 +34,7 @@ var (
backendLog = seelog.Disabled
adxrLog = btclog.Disabled
amgrLog = btclog.Disabled
cmgrLog = btclog.Disabled
bcdbLog = btclog.Disabled
bmgrLog = btclog.Disabled
btcdLog = btclog.Disabled
@ -51,6 +53,7 @@ var (
var subsystemLoggers = map[string]btclog.Logger{
"ADXR": adxrLog,
"AMGR": amgrLog,
"CMGR": cmgrLog,
"BCDB": bcdbLog,
"BMGR": bmgrLog,
"BTCD": btcdLog,
@ -97,6 +100,10 @@ func useLogger(subsystemID string, logger btclog.Logger) {
amgrLog = logger
addrmgr.UseLogger(logger)
case "CMGR":
cmgrLog = logger
connmgr.UseLogger(logger)
case "BCDB":
bcdbLog = logger
database.UseLogger(logger)

389
server.go
View file

@ -11,7 +11,6 @@ import (
"errors"
"fmt"
"math"
mrand "math/rand"
"net"
"runtime"
"strconv"
@ -25,6 +24,7 @@ import (
"github.com/btcsuite/btcd/blockchain/indexers"
"github.com/btcsuite/btcd/chaincfg"
"github.com/btcsuite/btcd/chaincfg/chainhash"
"github.com/btcsuite/btcd/connmgr"
"github.com/btcsuite/btcd/database"
"github.com/btcsuite/btcd/mempool"
"github.com/btcsuite/btcd/mining"
@ -35,13 +35,6 @@ import (
"github.com/btcsuite/btcutil/bloom"
)
const (
// These constants are used by the DNS seed code to pick a random last
// seen time.
secondsIn3Days int32 = 24 * 60 * 60 * 3
secondsIn4Days int32 = 24 * 60 * 60 * 4
)
const (
// defaultServices describes the default services that are supported by
// the server.
@ -54,12 +47,6 @@ const (
// retries when connecting to persistent peers. It is adjusted by the
// number of retries such that there is a retry backoff.
connectionRetryInterval = time.Second * 5
// maxConnectionRetryInterval is the max amount of time retrying of a
// persistent peer is allowed to grow to. This is necessary since the
// retry logic uses a backoff mechanism which increases the interval
// base done the number of retries that have been done.
maxConnectionRetryInterval = time.Minute * 5
)
var (
@ -109,7 +96,6 @@ type updatePeerHeightsMsg struct {
// peerState maintains state of inbound, persistent, outbound peers as well
// as banned peers and outbound groups.
type peerState struct {
pendingPeers map[string]*serverPeer
inboundPeers map[int32]*serverPeer
outboundPeers map[int32]*serverPeer
persistentPeers map[int32]*serverPeer
@ -124,22 +110,6 @@ func (ps *peerState) Count() int {
len(ps.persistentPeers)
}
// OutboundCount returns the count of known outbound peers.
func (ps *peerState) OutboundCount() int {
return len(ps.outboundPeers) + len(ps.persistentPeers)
}
// NeedMoreOutbound returns true if more outbound peers are required.
func (ps *peerState) NeedMoreOutbound() bool {
return ps.OutboundCount() < ps.maxOutboundPeers &&
ps.Count() < cfg.MaxPeers
}
// NeedMoreTries returns true if more outbound peer attempts can be tried.
func (ps *peerState) NeedMoreTries() bool {
return len(ps.pendingPeers) < 2*(ps.maxOutboundPeers-ps.OutboundCount())
}
// forAllOutboundPeers is a helper function that runs closure on all outbound
// peers known to peerState.
func (ps *peerState) forAllOutboundPeers(closure func(sp *serverPeer)) {
@ -151,14 +121,6 @@ func (ps *peerState) forAllOutboundPeers(closure func(sp *serverPeer)) {
}
}
// forPendingPeers is a helper function that runs closure on all pending peers
// known to peerState.
func (ps *peerState) forPendingPeers(closure func(sp *serverPeer)) {
for _, e := range ps.pendingPeers {
closure(e)
}
}
// forAllPeers is a helper function that runs closure on all peers known to
// peerState.
func (ps *peerState) forAllPeers(closure func(sp *serverPeer)) {
@ -182,17 +144,16 @@ type server struct {
listeners []net.Listener
chainParams *chaincfg.Params
addrManager *addrmgr.AddrManager
connManager *connmgr.ConnManager
sigCache *txscript.SigCache
rpcServer *rpcServer
blockManager *blockManager
txMemPool *mempool.TxPool
cpuMiner *CPUMiner
modifyRebroadcastInv chan interface{}
pendingPeers chan *serverPeer
newPeers chan *serverPeer
donePeers chan *serverPeer
banPeers chan *serverPeer
retryPeers chan *serverPeer
wakeup chan struct{}
query chan interface{}
relayInv chan relayMsg
@ -218,6 +179,7 @@ type server struct {
type serverPeer struct {
*peer.Peer
connReq *connmgr.ConnReq
server *server
persistent bool
continueHash *chainhash.Hash
@ -228,7 +190,7 @@ type serverPeer struct {
requestedBlocks map[chainhash.Hash]struct{}
filter *bloom.Filter
knownAddresses map[string]struct{}
banScore dynamicBanScore
banScore connmgr.DynamicBanScore
quit chan struct{}
// The following chans are used to sync blockmanager and server.
txProcessed chan struct{}
@ -1248,16 +1210,6 @@ func (s *server) handleAddPeerMsg(state *peerState, sp *serverPeer) bool {
// TODO: Check for max peers from a single IP.
// Limit max outbound peers.
if _, ok := state.pendingPeers[sp.Addr()]; ok {
if state.OutboundCount() >= state.maxOutboundPeers {
srvrLog.Infof("Max outbound peers reached [%d] - disconnecting "+
"peer %s", state.maxOutboundPeers, sp)
sp.Disconnect()
return false
}
}
// Limit max number of total peers.
if state.Count() >= cfg.MaxPeers {
srvrLog.Infof("Max peers reached [%d] - disconnecting peer %s",
@ -1279,8 +1231,6 @@ func (s *server) handleAddPeerMsg(state *peerState, sp *serverPeer) bool {
} else {
state.outboundPeers[sp.ID()] = sp
}
// Remove from pending peers.
delete(state.pendingPeers, sp.Addr())
}
return true
@ -1289,12 +1239,6 @@ func (s *server) handleAddPeerMsg(state *peerState, sp *serverPeer) bool {
// handleDonePeerMsg deals with peers that have signalled they are done. It is
// invoked from the peerHandler goroutine.
func (s *server) handleDonePeerMsg(state *peerState, sp *serverPeer) {
if _, ok := state.pendingPeers[sp.Addr()]; ok {
delete(state.pendingPeers, sp.Addr())
srvrLog.Debugf("Removed pending peer %s", sp)
return
}
var list map[int32]*serverPeer
if sp.persistent {
list = state.persistentPeers
@ -1304,23 +1248,21 @@ func (s *server) handleDonePeerMsg(state *peerState, sp *serverPeer) {
list = state.outboundPeers
}
if _, ok := list[sp.ID()]; ok {
// Issue an asynchronous reconnect if the peer was a
// persistent outbound connection.
if !sp.Inbound() && sp.persistent && atomic.LoadInt32(&s.shutdown) == 0 {
// Retry peer
sp2 := s.newOutboundPeer(sp.Addr(), sp.persistent)
if sp2 != nil {
go s.retryConn(sp2, false)
}
}
if !sp.Inbound() && sp.VersionKnown() {
state.outboundGroups[addrmgr.GroupKey(sp.NA())]--
}
if sp.persistent && sp.connReq != nil {
s.connManager.Disconnect(sp.connReq.ID())
}
delete(list, sp.ID())
srvrLog.Debugf("Removed peer %s", sp)
return
}
if sp.connReq != nil {
s.connManager.Remove(sp.connReq.ID())
}
// Update the address' last seen time if the peer has acknowledged
// our version and has sent us its version as well.
if sp.VerAckReceived() && sp.VersionKnown() && sp.NA() != nil {
@ -1428,6 +1370,11 @@ type getPeersMsg struct {
reply chan []*serverPeer
}
type getOutboundGroup struct {
key string
reply chan int
}
type getAddedNodesMsg struct {
reply chan []*serverPeer
}
@ -1485,13 +1432,11 @@ func (s *server) handleQuery(state *peerState, querymsg interface{}) {
}
// TODO(oga) if too many, nuke a non-perm peer.
sp := s.newOutboundPeer(msg.addr, msg.permanent)
if sp != nil {
go s.peerConnHandler(sp)
msg.reply <- nil
} else {
msg.reply <- errors.New("failed to add peer")
}
go s.connManager.Connect(&connmgr.ConnReq{
Addr: msg.addr,
Permanent: msg.permanent,
})
msg.reply <- nil
case removeNodeMsg:
found := disconnectPeer(state.persistentPeers, msg.cmp, func(sp *serverPeer) {
// Keep group counts ok since we remove from
@ -1504,6 +1449,13 @@ func (s *server) handleQuery(state *peerState, querymsg interface{}) {
} else {
msg.reply <- errors.New("peer not found")
}
case getOutboundGroup:
count, ok := state.outboundGroups[msg.key]
if ok {
msg.reply <- count
} else {
msg.reply <- 0
}
// Request a list of the persistent (added) peers.
case getAddedNodesMsg:
// Respond with a slice of the relavent peers.
@ -1630,53 +1582,6 @@ func (s *server) listenHandler(listener net.Listener) {
srvrLog.Tracef("Listener handler done for %s", listener.Addr())
}
// seedFromDNS uses DNS seeding to populate the address manager with peers.
func (s *server) seedFromDNS() {
// Nothing to do if DNS seeding is disabled.
if cfg.DisableDNSSeed {
return
}
for _, seeder := range activeNetParams.DNSSeeds {
go func(seeder string) {
randSource := mrand.New(mrand.NewSource(time.Now().UnixNano()))
seedpeers, err := dnsDiscover(seeder)
if err != nil {
discLog.Infof("DNS discovery failed on seed %s: %v", seeder, err)
return
}
numPeers := len(seedpeers)
discLog.Infof("%d addresses found from DNS seed %s", numPeers, seeder)
if numPeers == 0 {
return
}
addresses := make([]*wire.NetAddress, len(seedpeers))
// if this errors then we have *real* problems
intPort, _ := strconv.Atoi(activeNetParams.DefaultPort)
for i, peer := range seedpeers {
addresses[i] = new(wire.NetAddress)
addresses[i].SetAddress(peer, uint16(intPort))
// bitcoind seeds with addresses from
// a time randomly selected between 3
// and 7 days ago.
addresses[i].Timestamp = time.Now().Add(-1 *
time.Second * time.Duration(secondsIn3Days+
randSource.Int31n(secondsIn4Days)))
}
// Bitcoind uses a lookup of the dns seeder here. This
// is rather strange since the values looked up by the
// DNS seed lookups will vary quite a lot.
// to replicate this behaviour we put all addresses as
// having come from the first one.
s.addrManager.AddAddresses(addresses, addresses[0])
}(seeder)
}
}
// newOutboundPeer initializes a new outbound peer and setups the message
// listeners.
func (s *server) newOutboundPeer(addr string, persistent bool) *serverPeer {
@ -1691,15 +1596,6 @@ func (s *server) newOutboundPeer(addr string, persistent bool) *serverPeer {
return sp
}
// peerConnHandler handles peer connections. It must be run in a goroutine.
func (s *server) peerConnHandler(sp *serverPeer) {
err := s.establishConn(sp)
if err != nil {
srvrLog.Debugf("Failed to connect to %s: %v", sp.Addr(), err)
sp.Disconnect()
}
}
// peerDoneHandler handles peer disconnects by notifiying the server that it's
// done.
func (s *server) peerDoneHandler(sp *serverPeer) {
@ -1713,51 +1609,6 @@ func (s *server) peerDoneHandler(sp *serverPeer) {
close(sp.quit)
}
// establishConn establishes a connection to the peer.
func (s *server) establishConn(sp *serverPeer) error {
srvrLog.Debugf("Attempting to connect to %s", sp.Addr())
conn, err := btcdDial("tcp", sp.Addr())
if err != nil {
return err
}
sp.AssociateConnection(conn)
s.addrManager.Attempt(sp.NA())
return nil
}
// retryConn retries connection to the peer after the given duration. It must
// be run as a goroutine.
func (s *server) retryConn(sp *serverPeer, initialAttempt bool) {
retryDuration := connectionRetryInterval
for {
if initialAttempt {
retryDuration = 0
initialAttempt = false
} else {
srvrLog.Debugf("Retrying connection to %s in %s", sp.Addr(),
retryDuration)
}
select {
case <-time.After(retryDuration):
err := s.establishConn(sp)
if err != nil {
retryDuration += connectionRetryInterval
if retryDuration > maxConnectionRetryInterval {
retryDuration = maxConnectionRetryInterval
}
continue
}
return
case <-sp.quit:
return
case <-s.quit:
return
}
}
}
// peerHandler is used to handle peer operations such as adding and removing
// peers to and from the server, banning peers, and broadcasting messages to
// peers. It must be run in a goroutine.
@ -1773,7 +1624,6 @@ func (s *server) peerHandler() {
srvrLog.Tracef("Starting peer handler")
state := &peerState{
pendingPeers: make(map[string]*serverPeer),
inboundPeers: make(map[int32]*serverPeer),
persistentPeers: make(map[int32]*serverPeer),
outboundPeers: make(map[int32]*serverPeer),
@ -1784,20 +1634,19 @@ func (s *server) peerHandler() {
if cfg.MaxPeers < state.maxOutboundPeers {
state.maxOutboundPeers = cfg.MaxPeers
}
// Add peers discovered through DNS to the address manager.
s.seedFromDNS()
// Start up persistent peers.
permanentPeers := cfg.ConnectPeers
if len(permanentPeers) == 0 {
permanentPeers = cfg.AddPeers
}
for _, addr := range permanentPeers {
sp := s.newOutboundPeer(addr, true)
if sp != nil {
go s.retryConn(sp, true)
}
if !cfg.DisableDNSSeed {
// Add peers discovered through DNS to the address manager.
connmgr.SeedFromDNS(activeNetParams.Params, btcdLookup, func(addrs []*wire.NetAddress) {
// Bitcoind uses a lookup of the dns seeder here. This
// is rather strange since the values looked up by the
// DNS seed lookups will vary quite a lot.
// to replicate this behaviour we put all addresses as
// having come from the first one.
s.addrManager.AddAddresses(addrs, addrs[0])
})
}
go s.connManager.Start()
// if nothing else happens, wake us up soon.
time.AfterFunc(10*time.Second, func() { s.wakeup <- struct{}{} })
@ -1845,86 +1694,9 @@ out:
})
break out
}
// Don't try to connect to more peers when running on the
// simulation test network. The simulation network is only
// intended to connect to specified peers and actively avoid
// advertising and connecting to discovered peers.
if cfg.SimNet {
continue
}
// Only try connect to more peers if we actually need more.
if !state.NeedMoreOutbound() || len(cfg.ConnectPeers) > 0 ||
atomic.LoadInt32(&s.shutdown) != 0 {
state.forPendingPeers(func(sp *serverPeer) {
srvrLog.Tracef("Shutdown peer %s", sp)
sp.Disconnect()
})
continue
}
tries := 0
for state.NeedMoreOutbound() &&
state.NeedMoreTries() &&
atomic.LoadInt32(&s.shutdown) == 0 {
addr := s.addrManager.GetAddress("any")
if addr == nil {
break
}
key := addrmgr.GroupKey(addr.NetAddress())
// Address will not be invalid, local or unroutable
// because addrmanager rejects those on addition.
// Just check that we don't already have an address
// in the same group so that we are not connecting
// to the same network segment at the expense of
// others.
if state.outboundGroups[key] != 0 {
break
}
tries++
// After 100 bad tries exit the loop and we'll try again
// later.
if tries > 100 {
break
}
// Check that we don't have a pending connection to this addr.
addrStr := addrmgr.NetAddressKey(addr.NetAddress())
if _, ok := state.pendingPeers[addrStr]; ok {
continue
}
// XXX if we have limited that address skip
// only allow recent nodes (10mins) after we failed 30
// times
if tries < 30 && time.Now().Sub(addr.LastAttempt()) < 10*time.Minute {
continue
}
// allow nondefault ports after 50 failed tries.
if fmt.Sprintf("%d", addr.NetAddress().Port) !=
activeNetParams.DefaultPort && tries < 50 {
continue
}
tries = 0
sp := s.newOutboundPeer(addrStr, false)
if sp != nil {
go s.peerConnHandler(sp)
state.pendingPeers[sp.Addr()] = sp
}
}
// We need more peers, wake up in ten seconds and try again.
if state.NeedMoreOutbound() {
time.AfterFunc(10*time.Second, func() {
s.wakeup <- struct{}{}
})
}
}
s.connManager.Stop()
s.blockManager.Stop()
s.addrManager.Stop()
@ -1982,6 +1754,14 @@ func (s *server) ConnectedCount() int32 {
return <-replyChan
}
// OutboundGroupCount returns the number of peers connected to the given
// outbound group key.
func (s *server) OutboundGroupCount(key string) int {
replyChan := make(chan int)
s.query <- getOutboundGroup{key: key, reply: replyChan}
return <-replyChan
}
// AddedNodeInfo returns an array of btcjson.GetAddedNodeInfoResult structures
// describing the persistent (added) nodes.
func (s *server) AddedNodeInfo() []*serverPeer {
@ -2519,7 +2299,6 @@ func newServer(listenAddrs []string, db database.DB, chainParams *chaincfg.Param
newPeers: make(chan *serverPeer, cfg.MaxPeers),
donePeers: make(chan *serverPeer, cfg.MaxPeers),
banPeers: make(chan *serverPeer, cfg.MaxPeers),
retryPeers: make(chan *serverPeer, cfg.MaxPeers),
wakeup: make(chan struct{}),
query: make(chan interface{}),
relayInv: make(chan relayMsg, cfg.MaxPeers),
@ -2602,6 +2381,78 @@ func newServer(listenAddrs []string, db database.DB, chainParams *chaincfg.Param
}
s.cpuMiner = newCPUMiner(&policy, &s)
// Only setup a function to return new addresses to connect to when
// not running in connect-only mode. The simulation network is always
// in connect-only mode since it is only intended to connect to
// specified peers and actively avoid advertising and connecting to
// discovered peers in order to prevent it from becoming a public test
// network.
var newAddressFunc connmgr.AddressFunc
if !cfg.SimNet && len(cfg.ConnectPeers) == 0 {
newAddressFunc = func() (string, error) {
for tries := 0; tries < 100; tries++ {
addr := s.addrManager.GetAddress("any")
if addr == nil {
break
}
// Address will not be invalid, local or unroutable
// because addrmanager rejects those on addition.
// Just check that we don't already have an address
// in the same group so that we are not connecting
// to the same network segment at the expense of
// others.
key := addrmgr.GroupKey(addr.NetAddress())
if s.OutboundGroupCount(key) != 0 {
continue
}
// only allow recent nodes (10mins) after we failed 30
// times
if tries < 30 && time.Now().Sub(addr.LastAttempt()) < 10*time.Minute {
continue
}
// allow nondefault ports after 50 failed tries.
if fmt.Sprintf("%d", addr.NetAddress().Port) !=
activeNetParams.DefaultPort && tries < 50 {
continue
}
return addrmgr.NetAddressKey(addr.NetAddress()), nil
}
return "", errors.New("no valid connect address")
}
}
// Create a connection manager.
cmgr, err := connmgr.New(&connmgr.Config{
RetryDuration: connectionRetryInterval,
MaxOutbound: defaultMaxOutbound,
Dial: btcdDial,
OnConnection: func(c *connmgr.ConnReq, conn net.Conn) {
sp := s.newOutboundPeer(c.Addr, c.Permanent)
if sp != nil {
sp.AssociateConnection(conn)
sp.connReq = c
s.addrManager.Attempt(sp.NA())
}
},
GetNewAddress: newAddressFunc,
})
if err != nil {
return nil, err
}
s.connManager = cmgr
// Start up persistent peers.
permanentPeers := cfg.ConnectPeers
if len(permanentPeers) == 0 {
permanentPeers = cfg.AddPeers
}
for _, addr := range permanentPeers {
go s.connManager.Connect(&connmgr.ConnReq{Addr: addr, Permanent: true})
}
if !cfg.DisableRPC {
s.rpcServer, err = newRPCServer(cfg.RPCListeners, &policy, &s)
if err != nil {