lbcd/server.go

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2014-01-01 17:16:15 +01:00
// Copyright (c) 2013-2014 Conformal Systems LLC.
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// Use of this source code is governed by an ISC
// license that can be found in the LICENSE file.
package main
import (
"container/list"
"crypto/rand"
"encoding/binary"
"errors"
"fmt"
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"github.com/conformal/btcdb"
"github.com/conformal/btcjson"
"github.com/conformal/btcnet"
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"github.com/conformal/btcwire"
"math"
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"net"
"runtime"
"strconv"
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"sync"
"sync/atomic"
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"time"
)
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 (
// supportedServices describes which services are supported by the
// server.
supportedServices = btcwire.SFNodeNetwork
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// connectionRetryInterval is the amount of time to wait in between
// retries when connecting to persistent peers.
connectionRetryInterval = time.Second * 10
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// defaultMaxOutbound is the default number of max outbound peers.
defaultMaxOutbound = 8
)
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// broadcastMsg provides the ability to house a bitcoin message to be broadcast
// to all connected peers except specified excluded peers.
type broadcastMsg struct {
message btcwire.Message
excludePeers []*peer
}
// broadcastInventoryAdd is a type used to declare that the InvVect it contains
// needs to be added to the rebroadcast map
type broadcastInventoryAdd *btcwire.InvVect
// broadcastInventoryDel is a type used to declare that the InvVect it contains
// needs to be removed from the rebroadcast map
type broadcastInventoryDel *btcwire.InvVect
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// server provides a bitcoin server for handling communications to and from
// bitcoin peers.
type server struct {
nonce uint64
listeners []net.Listener
netParams *btcnet.Params
started int32 // atomic
shutdown int32 // atomic
shutdownSched int32 // atomic
bytesMutex sync.Mutex // For the following two fields.
bytesReceived uint64 // Total bytes received from all peers since start.
bytesSent uint64 // Total bytes sent by all peers since start.
addrManager *AddrManager
rpcServer *rpcServer
blockManager *blockManager
txMemPool *txMemPool
modifyRebroadcastInv chan interface{}
newPeers chan *peer
donePeers chan *peer
banPeers chan *peer
wakeup chan bool
query chan interface{}
relayInv chan *btcwire.InvVect
broadcast chan broadcastMsg
wg sync.WaitGroup
quit chan bool
nat NAT
db btcdb.Db
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}
type peerState struct {
peers *list.List
outboundPeers *list.List
persistentPeers *list.List
banned map[string]time.Time
outboundGroups map[string]int
maxOutboundPeers int
}
// randomUint16Number returns a random uint16 in a specified input range. Note
// that the range is in zeroth ordering; if you pass it 1800, you will get
// values from 0 to 1800.
func randomUint16Number(max uint16) uint16 {
// In order to avoid modulo bias and ensure every possible outcome in
// [0, max) has equal probability, the random number must be sampled
// from a random source that has a range limited to a multiple of the
// modulus.
var randomNumber uint16
var limitRange = (math.MaxUint16 / max) * max
for {
binary.Read(rand.Reader, binary.LittleEndian, &randomNumber)
if randomNumber < limitRange {
return (randomNumber % max)
}
}
}
// AddRebroadcastInventory adds 'iv' to the list of inventories to be
// rebroadcasted at random intervals until they show up in a block.
func (s *server) AddRebroadcastInventory(iv *btcwire.InvVect) {
// Ignore if shutting down.
if atomic.LoadInt32(&s.shutdown) != 0 {
return
}
s.modifyRebroadcastInv <- broadcastInventoryAdd(iv)
}
// RemoveRebroadcastInventory removes 'iv' from the list of items to be
// rebroadcasted if present.
func (s *server) RemoveRebroadcastInventory(iv *btcwire.InvVect) {
// Ignore if shutting down.
if atomic.LoadInt32(&s.shutdown) != 0 {
return
}
s.modifyRebroadcastInv <- broadcastInventoryDel(iv)
}
func (p *peerState) Count() int {
return p.peers.Len() + p.outboundPeers.Len() + p.persistentPeers.Len()
}
func (p *peerState) OutboundCount() int {
return p.outboundPeers.Len() + p.persistentPeers.Len()
}
func (p *peerState) NeedMoreOutbound() bool {
return p.OutboundCount() < p.maxOutboundPeers &&
p.Count() < cfg.MaxPeers
}
// forAllOutboundPeers is a helper function that runs closure on all outbound
// peers known to peerState.
func (p *peerState) forAllOutboundPeers(closure func(p *peer)) {
for e := p.outboundPeers.Front(); e != nil; e = e.Next() {
closure(e.Value.(*peer))
}
for e := p.persistentPeers.Front(); e != nil; e = e.Next() {
closure(e.Value.(*peer))
}
}
// forAllPeers is a helper function that runs closure on all peers known to
// peerState.
func (p *peerState) forAllPeers(closure func(p *peer)) {
for e := p.peers.Front(); e != nil; e = e.Next() {
closure(e.Value.(*peer))
}
p.forAllOutboundPeers(closure)
}
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// handleAddPeerMsg deals with adding new peers. It is invoked from the
// peerHandler goroutine.
func (s *server) handleAddPeerMsg(state *peerState, p *peer) bool {
if p == nil {
return false
}
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// Ignore new peers if we're shutting down.
if atomic.LoadInt32(&s.shutdown) != 0 {
srvrLog.Infof("New peer %s ignored - server is shutting "+
"down", p)
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p.Shutdown()
return false
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}
// Disconnect banned peers.
host, _, err := net.SplitHostPort(p.addr)
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if err != nil {
srvrLog.Debugf("can't split hostport %v", err)
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p.Shutdown()
return false
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}
if banEnd, ok := state.banned[host]; ok {
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if time.Now().Before(banEnd) {
srvrLog.Debugf("Peer %s is banned for another %v - "+
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"disconnecting", host, banEnd.Sub(time.Now()))
p.Shutdown()
return false
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}
srvrLog.Infof("Peer %s is no longer banned", host)
delete(state.banned, host)
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}
// TODO: Check for max peers from a single IP.
// Limit max number of total peers.
if state.Count() >= cfg.MaxPeers {
srvrLog.Infof("Max peers reached [%d] - disconnecting "+
"peer %s", cfg.MaxPeers, p)
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p.Shutdown()
// TODO(oga) how to handle permanent peers here?
// they should be rescheduled.
return false
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}
// Add the new peer and start it.
srvrLog.Debugf("New peer %s", p)
if p.inbound {
state.peers.PushBack(p)
p.Start()
} else {
state.outboundGroups[GroupKey(p.na)]++
if p.persistent {
state.persistentPeers.PushBack(p)
} else {
state.outboundPeers.PushBack(p)
}
}
return true
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}
// handleDonePeerMsg deals with peers that have signalled they are done. It is
// invoked from the peerHandler goroutine.
func (s *server) handleDonePeerMsg(state *peerState, p *peer) {
var list *list.List
if p.persistent {
list = state.persistentPeers
} else if p.inbound {
list = state.peers
} else {
list = state.outboundPeers
}
for e := list.Front(); e != nil; e = e.Next() {
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if e.Value == p {
// Issue an asynchronous reconnect if the peer was a
// persistent outbound connection.
if !p.inbound && p.persistent &&
atomic.LoadInt32(&s.shutdown) == 0 {
e.Value = newOutboundPeer(s, p.addr, true)
return
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}
if !p.inbound {
state.outboundGroups[GroupKey(p.na)]--
}
list.Remove(e)
srvrLog.Debugf("Removed peer %s", p)
return
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}
}
// If we get here it means that either we didn't know about the peer
// or we purposefully deleted it.
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}
// handleBanPeerMsg deals with banning peers. It is invoked from the
// peerHandler goroutine.
func (s *server) handleBanPeerMsg(state *peerState, p *peer) {
host, _, err := net.SplitHostPort(p.addr)
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if err != nil {
srvrLog.Debugf("can't split ban peer %s %v", p.addr, err)
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return
}
direction := directionString(p.inbound)
srvrLog.Infof("Banned peer %s (%s) for %v", host, direction,
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cfg.BanDuration)
state.banned[host] = time.Now().Add(cfg.BanDuration)
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}
// handleRelayInvMsg deals with relaying inventory to peers that are not already
// known to have it. It is invoked from the peerHandler goroutine.
func (s *server) handleRelayInvMsg(state *peerState, iv *btcwire.InvVect) {
state.forAllPeers(func(p *peer) {
if !p.Connected() {
return
}
// Queue the inventory to be relayed with the next batch. It
// will be ignored if the peer is already known to have the
// inventory.
p.QueueInventory(iv)
})
}
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// handleBroadcastMsg deals with broadcasting messages to peers. It is invoked
// from the peerHandler goroutine.
func (s *server) handleBroadcastMsg(state *peerState, bmsg *broadcastMsg) {
state.forAllPeers(func(p *peer) {
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excluded := false
for _, ep := range bmsg.excludePeers {
if p == ep {
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excluded = true
}
}
// Don't broadcast to still connecting outbound peers .
if !p.Connected() {
excluded = true
}
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if !excluded {
p.QueueMessage(bmsg.message, nil)
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}
})
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}
type getConnCountMsg struct {
reply chan int
}
type getPeerInfoMsg struct {
reply chan []*btcjson.GetPeerInfoResult
}
type addNodeMsg struct {
addr string
permanent bool
reply chan error
}
type delNodeMsg struct {
addr string
reply chan error
}
type getAddedNodesMsg struct {
reply chan []*peer
}
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// handleQuery is the central handler for all queries and commands from other
// goroutines related to peer state.
func (s *server) handleQuery(querymsg interface{}, state *peerState) {
switch msg := querymsg.(type) {
case getConnCountMsg:
nconnected := 0
state.forAllPeers(func(p *peer) {
if p.Connected() {
nconnected++
}
})
msg.reply <- nconnected
case getPeerInfoMsg:
syncPeer := s.blockManager.SyncPeer()
infos := make([]*btcjson.GetPeerInfoResult, 0, state.peers.Len())
state.forAllPeers(func(p *peer) {
if !p.Connected() {
return
}
// A lot of this will make the race detector go mad,
// however it is statistics for purely informational purposes
// and we don't really care if they are raced to get the new
// version.
p.StatsMtx.Lock()
info := &btcjson.GetPeerInfoResult{
Addr: p.addr,
Services: fmt.Sprintf("%08d", p.services),
LastSend: p.lastSend.Unix(),
LastRecv: p.lastRecv.Unix(),
BytesSent: p.bytesSent,
BytesRecv: p.bytesReceived,
ConnTime: p.timeConnected.Unix(),
Version: p.protocolVersion,
SubVer: p.userAgent,
Inbound: p.inbound,
StartingHeight: p.lastBlock,
BanScore: 0,
SyncNode: p == syncPeer,
}
info.PingTime = p.lastPingMicros
if p.lastPingNonce != 0 {
wait := time.Now().Sub(p.lastPingTime).Nanoseconds()
// We actually want microseconds.
info.PingWait = wait / 1000
}
p.StatsMtx.Unlock()
infos = append(infos, info)
})
msg.reply <- infos
case addNodeMsg:
// XXX(oga) duplicate oneshots?
if msg.permanent {
for e := state.persistentPeers.Front(); e != nil; e = e.Next() {
peer := e.Value.(*peer)
if peer.addr == msg.addr {
msg.reply <- errors.New("peer already connected")
return
}
}
}
// TODO(oga) if too many, nuke a non-perm peer.
if s.handleAddPeerMsg(state,
newOutboundPeer(s, msg.addr, msg.permanent)) {
msg.reply <- nil
} else {
msg.reply <- errors.New("failed to add peer")
}
case delNodeMsg:
found := false
for e := state.persistentPeers.Front(); e != nil; e = e.Next() {
peer := e.Value.(*peer)
if peer.addr == msg.addr {
// Keep group counts ok since we remove from
// the list now.
state.outboundGroups[GroupKey(peer.na)]--
// This is ok because we are not continuing
// to iterate so won't corrupt the loop.
state.persistentPeers.Remove(e)
peer.Disconnect()
found = true
break
}
}
if found {
msg.reply <- nil
} else {
msg.reply <- errors.New("peer not found")
}
// Request a list of the persistent (added) peers.
case getAddedNodesMsg:
// Respond with a slice of the relavent peers.
peers := make([]*peer, 0, state.persistentPeers.Len())
for e := state.persistentPeers.Front(); e != nil; e = e.Next() {
peer := e.Value.(*peer)
peers = append(peers, peer)
}
msg.reply <- peers
}
}
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// listenHandler is the main listener which accepts incoming connections for the
// server. It must be run as a goroutine.
func (s *server) listenHandler(listener net.Listener) {
srvrLog.Infof("Server listening on %s", listener.Addr())
for atomic.LoadInt32(&s.shutdown) == 0 {
conn, err := listener.Accept()
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if err != nil {
// Only log the error if we're not forcibly shutting down.
if atomic.LoadInt32(&s.shutdown) == 0 {
srvrLog.Errorf("can't accept connection: %v",
err)
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}
continue
}
s.AddPeer(newInboundPeer(s, conn))
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}
s.wg.Done()
srvrLog.Tracef("Listener handler done for %s", listener.Addr())
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}
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// 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 {
seedpeers := dnsDiscover(seeder)
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if len(seedpeers) == 0 {
continue
}
addresses := make([]*btcwire.NetAddress, len(seedpeers))
// if this errors then we have *real* problems
intPort, _ := strconv.Atoi(activeNetParams.DefaultPort)
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for i, peer := range seedpeers {
addresses[i] = new(btcwire.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+
s.addrManager.rand.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])
}
// XXX if this is empty do we want to use hardcoded
// XXX peers like bitcoind does?
}
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// 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 a a goroutine.
func (s *server) peerHandler() {
// Start the address manager and block manager, both of which are needed
// by peers. This is done here since their lifecycle is closely tied
// to this handler and rather than adding more channels to sychronize
// things, it's easier and slightly faster to simply start and stop them
// in this handler.
s.addrManager.Start()
s.blockManager.Start()
srvrLog.Tracef("Starting peer handler")
state := &peerState{
peers: list.New(),
persistentPeers: list.New(),
outboundPeers: list.New(),
banned: make(map[string]time.Time),
maxOutboundPeers: defaultMaxOutbound,
outboundGroups: make(map[string]int),
}
if cfg.MaxPeers < state.maxOutboundPeers {
state.maxOutboundPeers = cfg.MaxPeers
}
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// 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 {
s.handleAddPeerMsg(state, newOutboundPeer(s, addr, true))
}
// if nothing else happens, wake us up soon.
time.AfterFunc(10*time.Second, func() { s.wakeup <- true })
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out:
for {
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select {
// New peers connected to the server.
case p := <-s.newPeers:
s.handleAddPeerMsg(state, p)
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// Disconnected peers.
case p := <-s.donePeers:
s.handleDonePeerMsg(state, p)
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// Peer to ban.
case p := <-s.banPeers:
s.handleBanPeerMsg(state, p)
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// New inventory to potentially be relayed to other peers.
case invMsg := <-s.relayInv:
s.handleRelayInvMsg(state, invMsg)
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// Message to broadcast to all connected peers except those
// which are excluded by the message.
case bmsg := <-s.broadcast:
s.handleBroadcastMsg(state, &bmsg)
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// Used by timers below to wake us back up.
case <-s.wakeup:
// this page left intentionally blank
case qmsg := <-s.query:
s.handleQuery(qmsg, state)
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// Shutdown the peer handler.
case <-s.quit:
// Shutdown peers.
state.forAllPeers(func(p *peer) {
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p.Shutdown()
})
break out
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}
// 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 {
continue
}
tries := 0
for state.NeedMoreOutbound() &&
atomic.LoadInt32(&s.shutdown) == 0 {
// We bias like bitcoind does, 10 for no outgoing
// up to 90 (8) for the selection of new vs tried
//addresses.
nPeers := state.OutboundCount()
if nPeers > 8 {
nPeers = 8
}
addr := s.addrManager.GetAddress("any", 10+nPeers*10)
if addr == nil {
break
}
key := GroupKey(addr.na)
// 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. bitcoind breaks out of the loop here, but
// we continue to try other addresses.
if state.outboundGroups[key] != 0 {
continue
}
tries++
// After 100 bad tries exit the loop and we'll try again
// later.
if tries > 100 {
break
}
// XXX if we have limited that address skip
// only allow recent nodes (10mins) after we failed 30
// times
if time.Now().After(addr.lastattempt.Add(10*time.Minute)) &&
tries < 30 {
continue
}
// allow nondefault ports after 50 failed tries.
if fmt.Sprintf("%d", addr.na.Port) !=
activeNetParams.DefaultPort && tries < 50 {
continue
}
addrStr := NetAddressKey(addr.na)
tries = 0
// any failure will be due to banned peers etc. we have
// already checked that we have room for more peers.
if s.handleAddPeerMsg(state,
newOutboundPeer(s, addrStr, false)) {
}
}
// We we need more peers, wake up in ten seconds and try again.
if state.NeedMoreOutbound() {
time.AfterFunc(10*time.Second, func() {
s.wakeup <- true
})
}
}
s.blockManager.Stop()
s.addrManager.Stop()
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s.wg.Done()
srvrLog.Tracef("Peer handler done")
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}
// AddPeer adds a new peer that has already been connected to the server.
func (s *server) AddPeer(p *peer) {
s.newPeers <- p
}
// BanPeer bans a peer that has already been connected to the server by ip.
func (s *server) BanPeer(p *peer) {
s.banPeers <- p
}
// RelayInventory relays the passed inventory to all connected peers that are
// not already known to have it.
func (s *server) RelayInventory(invVect *btcwire.InvVect) {
s.relayInv <- invVect
}
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// BroadcastMessage sends msg to all peers currently connected to the server
// except those in the passed peers to exclude.
func (s *server) BroadcastMessage(msg btcwire.Message, exclPeers ...*peer) {
// XXX: Need to determine if this is an alert that has already been
// broadcast and refrain from broadcasting again.
bmsg := broadcastMsg{message: msg, excludePeers: exclPeers}
s.broadcast <- bmsg
}
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// ConnectedCount returns the number of currently connected peers.
func (s *server) ConnectedCount() int {
replyChan := make(chan int)
s.query <- getConnCountMsg{reply: replyChan}
return <-replyChan
}
// AddedNodeInfo returns an array of btcjson.GetAddedNodeInfoResult structures
// describing the persistent (added) nodes.
func (s *server) AddedNodeInfo() []*peer {
replyChan := make(chan []*peer)
s.query <- getAddedNodesMsg{reply: replyChan}
return <-replyChan
}
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// PeerInfo returns an array of PeerInfo structures describing all connected
// peers.
func (s *server) PeerInfo() []*btcjson.GetPeerInfoResult {
replyChan := make(chan []*btcjson.GetPeerInfoResult)
s.query <- getPeerInfoMsg{reply: replyChan}
return <-replyChan
}
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// AddAddr adds `addr' as a new outbound peer. If permanent is true then the
// peer will be persistent and reconnect if the connection is lost.
// It is an error to call this with an already existing peer.
func (s *server) AddAddr(addr string, permanent bool) error {
replyChan := make(chan error)
s.query <- addNodeMsg{addr: addr, permanent: permanent, reply: replyChan}
return <-replyChan
}
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// RemoveAddr removes `addr' from the list of persistent peers if present.
// An error will be returned if the peer was not found.
func (s *server) RemoveAddr(addr string) error {
replyChan := make(chan error)
s.query <- delNodeMsg{addr: addr, reply: replyChan}
return <-replyChan
}
// AddBytesSent adds the passed number of bytes to the total bytes sent counter
// for the server. It is safe for concurrent access.
func (s *server) AddBytesSent(bytesSent uint64) {
s.bytesMutex.Lock()
defer s.bytesMutex.Unlock()
s.bytesSent += bytesSent
}
// AddBytesReceived adds the passed number of bytes to the total bytes received
// counter for the server. It is safe for concurrent access.
func (s *server) AddBytesReceived(bytesReceived uint64) {
s.bytesMutex.Lock()
defer s.bytesMutex.Unlock()
s.bytesReceived += bytesReceived
}
// NetTotals returns the sum of all bytes received and sent across the network
// for all peers. It is safe for concurrent access.
func (s *server) NetTotals() (uint64, uint64) {
s.bytesMutex.Lock()
defer s.bytesMutex.Unlock()
return s.bytesReceived, s.bytesSent
}
// rebroadcastHandler keeps track of user submitted inventories that we have
// sent out but have not yet made it into a block. We periodically rebroadcast
// them in case our peers restarted or otherwise lost track of them.
func (s *server) rebroadcastHandler() {
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// Wait 5 min before first tx rebroadcast.
timer := time.NewTimer(5 * time.Minute)
pendingInvs := make(map[btcwire.InvVect]struct{})
out:
for {
select {
case riv := <-s.modifyRebroadcastInv:
switch msg := riv.(type) {
// Incoming InvVects are added to our map of RPC txs.
case broadcastInventoryAdd:
pendingInvs[*msg] = struct{}{}
// When an InvVect has been added to a block, we can
// now remove it, if it was present.
case broadcastInventoryDel:
if _, ok := pendingInvs[*msg]; ok {
delete(pendingInvs, *msg)
}
}
case <-timer.C:
// Any inventory we have has not made it into a block
// yet. We periodically resubmit them until they have.
for iv := range pendingInvs {
ivCopy := iv
s.RelayInventory(&ivCopy)
}
// Process at a random time up to 30mins (in seconds)
// in the future.
timer.Reset(time.Second *
time.Duration(randomUint16Number(1800)))
case <-s.quit:
break out
}
}
timer.Stop()
// Drain channels before exiting so nothing is left waiting around
// to send.
cleanup:
for {
select {
case <-s.modifyRebroadcastInv:
default:
break cleanup
}
}
s.wg.Done()
}
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// Start begins accepting connections from peers.
func (s *server) Start() {
// Already started?
if atomic.AddInt32(&s.started, 1) != 1 {
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return
}
srvrLog.Trace("Starting server")
// Start all the listeners. There will not be any if listening is
// disabled.
for _, listener := range s.listeners {
s.wg.Add(1)
go s.listenHandler(listener)
}
// Start the peer handler which in turn starts the address and block
// managers.
s.wg.Add(1)
go s.peerHandler()
if s.nat != nil {
s.wg.Add(1)
go s.upnpUpdateThread()
}
if !cfg.DisableRPC {
s.wg.Add(1)
// Start the rebroadcastHandler, which ensures user tx received by
// the RPC server are rebroadcast until being included in a block.
go s.rebroadcastHandler()
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s.rpcServer.Start()
}
}
// Stop gracefully shuts down the server by stopping and disconnecting all
// peers and the main listener.
func (s *server) Stop() error {
// Make sure this only happens once.
if atomic.AddInt32(&s.shutdown, 1) != 1 {
srvrLog.Infof("Server is already in the process of shutting down")
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return nil
}
srvrLog.Warnf("Server shutting down")
// Stop all the listeners. There will not be any listeners if
// listening is disabled.
for _, listener := range s.listeners {
err := listener.Close()
if err != nil {
return err
}
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}
// Shutdown the RPC server if it's not disabled.
if !cfg.DisableRPC {
s.rpcServer.Stop()
}
// Signal the remaining goroutines to quit.
close(s.quit)
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return nil
}
// WaitForShutdown blocks until the main listener and peer handlers are stopped.
func (s *server) WaitForShutdown() {
s.wg.Wait()
}
// ScheduleShutdown schedules a server shutdown after the specified duration.
// It also dynamically adjusts how often to warn the server is going down based
// on remaining duration.
func (s *server) ScheduleShutdown(duration time.Duration) {
// Don't schedule shutdown more than once.
if atomic.AddInt32(&s.shutdownSched, 1) != 1 {
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return
}
srvrLog.Warnf("Server shutdown in %v", duration)
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go func() {
remaining := duration
tickDuration := dynamicTickDuration(remaining)
done := time.After(remaining)
ticker := time.NewTicker(tickDuration)
out:
for {
select {
case <-done:
ticker.Stop()
s.Stop()
break out
case <-ticker.C:
remaining = remaining - tickDuration
if remaining < time.Second {
continue
}
// Change tick duration dynamically based on remaining time.
newDuration := dynamicTickDuration(remaining)
if tickDuration != newDuration {
tickDuration = newDuration
ticker.Stop()
ticker = time.NewTicker(tickDuration)
}
srvrLog.Warnf("Server shutdown in %v", remaining)
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}
}
}()
}
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// parseListeners splits the list of listen addresses passed in addrs into
// IPv4 and IPv6 slices and returns them. This allows easy creation of the
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// listeners on the correct interface "tcp4" and "tcp6". It also properly
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// detects addresses which apply to "all interfaces" and adds the address to
// both slices.
func parseListeners(addrs []string) ([]string, []string, bool, error) {
ipv4ListenAddrs := make([]string, 0, len(addrs)*2)
ipv6ListenAddrs := make([]string, 0, len(addrs)*2)
haveWildcard := false
for _, addr := range addrs {
host, _, err := net.SplitHostPort(addr)
if err != nil {
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// Shouldn't happen due to already being normalized.
return nil, nil, false, err
}
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// Empty host or host of * on plan9 is both IPv4 and IPv6.
if host == "" || (host == "*" && runtime.GOOS == "plan9") {
ipv4ListenAddrs = append(ipv4ListenAddrs, addr)
ipv6ListenAddrs = append(ipv6ListenAddrs, addr)
haveWildcard = true
continue
}
// Parse the IP.
ip := net.ParseIP(host)
if ip == nil {
return nil, nil, false, fmt.Errorf("'%s' is not a "+
"valid IP address", host)
}
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// To4 returns nil when the IP is not an IPv4 address, so use
// this determine the address type.
if ip.To4() == nil {
ipv6ListenAddrs = append(ipv6ListenAddrs, addr)
} else {
ipv4ListenAddrs = append(ipv4ListenAddrs, addr)
}
}
return ipv4ListenAddrs, ipv6ListenAddrs, haveWildcard, nil
}
func (s *server) upnpUpdateThread() {
// Go off immediately to prevent code duplication, thereafter we renew
// lease every 15 minutes.
timer := time.NewTimer(0 * time.Second)
lport, _ := strconv.ParseInt(activeNetParams.DefaultPort, 10, 16)
first := true
out:
for {
select {
case <-timer.C:
// TODO(oga) pick external port more cleverly
// TODO(oga) know which ports we are listening to on an external net.
// TODO(oga) if specific listen port doesn't work then ask for wildcard
// listen port?
// XXX this assumes timeout is in seconds.
listenPort, err := s.nat.AddPortMapping("tcp", int(lport), int(lport),
"btcd listen port", 20*60)
if err != nil {
srvrLog.Warnf("can't add UPnP port mapping: %v", err)
}
if first && err == nil {
// TODO(oga): look this up periodically to see if upnp domain changed
// and so did ip.
externalip, err := s.nat.GetExternalAddress()
if err != nil {
srvrLog.Warnf("UPnP can't get external address: %v", err)
continue out
}
na := btcwire.NewNetAddressIPPort(externalip, uint16(listenPort),
btcwire.SFNodeNetwork)
s.addrManager.addLocalAddress(na, UpnpPrio)
srvrLog.Warnf("Successfully bound via UPnP to %s", NetAddressKey(na))
first = false
}
timer.Reset(time.Minute * 15)
case <-s.quit:
break out
}
}
timer.Stop()
if err := s.nat.DeletePortMapping("tcp", int(lport), int(lport)); err != nil {
srvrLog.Warnf("unable to remove UPnP port mapping: %v", err)
} else {
srvrLog.Debugf("succesfully disestablished UPnP port mapping")
}
s.wg.Done()
}
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// newServer returns a new btcd server configured to listen on addr for the
// bitcoin network type specified by netParams. Use start to begin accepting
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// connections from peers.
func newServer(listenAddrs []string, db btcdb.Db, netParams *btcnet.Params) (*server, error) {
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nonce, err := btcwire.RandomUint64()
if err != nil {
return nil, err
}
amgr := NewAddrManager()
var listeners []net.Listener
var nat NAT
if !cfg.DisableListen {
ipv4Addrs, ipv6Addrs, wildcard, err :=
parseListeners(listenAddrs)
if err != nil {
return nil, err
}
listeners = make([]net.Listener, 0, len(ipv4Addrs)+len(ipv6Addrs))
discover := true
if len(cfg.ExternalIPs) != 0 {
discover = false
// if this fails we have real issues.
port, _ := strconv.ParseUint(
activeNetParams.DefaultPort, 10, 16)
for _, sip := range cfg.ExternalIPs {
eport := uint16(port)
host, portstr, err := net.SplitHostPort(sip)
if err != nil {
// no port, use default.
host = sip
} else {
port, err := strconv.ParseUint(
portstr, 10, 16)
if err != nil {
srvrLog.Warnf("Can not parse "+
"port from %s for "+
"externalip: %v", sip,
err)
continue
}
eport = uint16(port)
}
na, err := hostToNetAddress(host, eport,
btcwire.SFNodeNetwork)
if err != nil {
srvrLog.Warnf("Not adding %s as "+
"externalip: %v", sip, err)
continue
}
amgr.addLocalAddress(na, ManualPrio)
}
} else if discover && cfg.Upnp {
nat, err = Discover()
if err != nil {
srvrLog.Warnf("Can't discover upnp: %v", err)
}
// nil nat here is fine, just means no upnp on network.
}
// TODO(oga) nonstandard port...
if wildcard {
port, err :=
strconv.ParseUint(activeNetParams.DefaultPort,
10, 16)
if err != nil {
// I can't think of a cleaner way to do this...
goto nowc
}
addrs, err := net.InterfaceAddrs()
for _, a := range addrs {
ip, _, err := net.ParseCIDR(a.String())
if err != nil {
continue
}
na := btcwire.NewNetAddressIPPort(ip,
uint16(port), btcwire.SFNodeNetwork)
if discover {
amgr.addLocalAddress(na, InterfacePrio)
}
}
}
nowc:
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for _, addr := range ipv4Addrs {
listener, err := net.Listen("tcp4", addr)
if err != nil {
srvrLog.Warnf("Can't listen on %s: %v", addr,
err)
continue
}
listeners = append(listeners, listener)
if discover {
if na, err := deserialiseNetAddress(addr); err == nil {
amgr.addLocalAddress(na, BoundPrio)
}
}
}
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for _, addr := range ipv6Addrs {
listener, err := net.Listen("tcp6", addr)
if err != nil {
srvrLog.Warnf("Can't listen on %s: %v", addr,
err)
continue
}
listeners = append(listeners, listener)
if discover {
if na, err := deserialiseNetAddress(addr); err == nil {
amgr.addLocalAddress(na, BoundPrio)
}
}
}
if len(listeners) == 0 {
return nil, errors.New("No valid listen address")
}
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}
s := server{
nonce: nonce,
listeners: listeners,
netParams: netParams,
addrManager: amgr,
newPeers: make(chan *peer, cfg.MaxPeers),
donePeers: make(chan *peer, cfg.MaxPeers),
banPeers: make(chan *peer, cfg.MaxPeers),
wakeup: make(chan bool),
query: make(chan interface{}),
relayInv: make(chan *btcwire.InvVect, cfg.MaxPeers),
broadcast: make(chan broadcastMsg, cfg.MaxPeers),
quit: make(chan bool),
modifyRebroadcastInv: make(chan interface{}),
nat: nat,
db: db,
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}
bm, err := newBlockManager(&s)
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if err != nil {
return nil, err
}
s.blockManager = bm
s.txMemPool = newTxMemPool(&s)
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if !cfg.DisableRPC {
s.rpcServer, err = newRPCServer(cfg.RPCListeners, &s)
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if err != nil {
return nil, err
}
}
return &s, nil
}
// dynamicTickDuration is a convenience function used to dynamically choose a
// tick duration based on remaining time. It is primarily used during
// server shutdown to make shutdown warnings more frequent as the shutdown time
// approaches.
func dynamicTickDuration(remaining time.Duration) time.Duration {
switch {
case remaining <= time.Second*5:
return time.Second
case remaining <= time.Second*15:
return time.Second * 5
case remaining <= time.Minute:
return time.Second * 15
case remaining <= time.Minute*5:
return time.Minute
case remaining <= time.Minute*15:
return time.Minute * 5
case remaining <= time.Hour:
return time.Minute * 15
}
return time.Hour
}