// 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() {
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
}
if !p.inbound {
state.outboundGroups[addrmgr.GroupKey(p.na)]--
}
list.Remove(e)
srvrLog.Debugf("Removed peer %s", p)
return
}
}
// If we get here it means that either we didn't know about the peer
// or we purposefully deleted it.
}
// 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
}
// 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)
p.Shutdown()
return false
}
// Disconnect banned peers.
host, _, err := net.SplitHostPort(p.addr)
if err != nil {
srvrLog.Debugf("can't split hostport %v", err)
p.Shutdown()
return false
}
if banEnd, ok := state.banned[host]; ok {
if time.Now().Before(banEnd) {
srvrLog.Debugf("Peer %s is banned for another %v - "+
"disconnecting", host, banEnd.Sub(time.Now()))
p.Shutdown()
return false
}
srvrLog.Infof("Peer %s is no longer banned", host)
delete(state.banned, host)
}
// 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)
p.Shutdown()
// TODO(oga) how to handle permanent peers here?
// they should be rescheduled.
return false
}
// 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[addrmgr.GroupKey(p.na)]++
if p.persistent {
state.persistentPeers.PushBack(p)
} else {
state.outboundPeers.PushBack(p)
}
}
return true
}
// TestGroupKey tests the GroupKey function to ensure it properly groups various
// IP addresses.
func TestGroupKey(t *testing.T) {
tests := []struct {
name string
ip string
expected string
}{
// Local addresses.
{name: "ipv4 localhost", ip: "127.0.0.1", expected: "local"},
{name: "ipv6 localhost", ip: "::1", expected: "local"},
{name: "ipv4 zero", ip: "0.0.0.0", expected: "local"},
{name: "ipv4 first octet zero", ip: "0.1.2.3", expected: "local"},
// Unroutable addresses.
{name: "ipv4 invalid bcast", ip: "255.255.255.255", expected: "unroutable"},
{name: "ipv4 rfc1918 10/8", ip: "10.1.2.3", expected: "unroutable"},
{name: "ipv4 rfc1918 172.16/12", ip: "172.16.1.2", expected: "unroutable"},
{name: "ipv4 rfc1918 192.168/16", ip: "192.168.1.2", expected: "unroutable"},
{name: "ipv6 rfc3849 2001:db8::/32", ip: "2001:db8::1234", expected: "unroutable"},
{name: "ipv4 rfc3927 169.254/16", ip: "169.254.1.2", expected: "unroutable"},
{name: "ipv6 rfc4193 fc00::/7", ip: "fc00::1234", expected: "unroutable"},
{name: "ipv6 rfc4843 2001:10::/28", ip: "2001:10::1234", expected: "unroutable"},
{name: "ipv6 rfc4862 fe80::/64", ip: "fe80::1234", expected: "unroutable"},
// IPv4 normal.
{name: "ipv4 normal class a", ip: "12.1.2.3", expected: "12.1.0.0"},
{name: "ipv4 normal class b", ip: "173.1.2.3", expected: "173.1.0.0"},
{name: "ipv4 normal class c", ip: "196.1.2.3", expected: "196.1.0.0"},
// IPv6/IPv4 translations.
{name: "ipv6 rfc3964 with ipv4 encap", ip: "2002:0c01:0203::", expected: "12.1.0.0"},
{name: "ipv6 rfc4380 toredo ipv4", ip: "2001:0:1234::f3fe:fdfc", expected: "12.1.0.0"},
{name: "ipv6 rfc6052 well-known prefix with ipv4", ip: "64:ff9b::0c01:0203", expected: "12.1.0.0"},
{name: "ipv6 rfc6145 translated ipv4", ip: "::ffff:0:0c01:0203", expected: "12.1.0.0"},
// Tor.
{name: "ipv6 tor onioncat", ip: "fd87:d87e:eb43:1234::5678", expected: "tor:2"},
{name: "ipv6 tor onioncat 2", ip: "fd87:d87e:eb43:1245::6789", expected: "tor:2"},
{name: "ipv6 tor onioncat 3", ip: "fd87:d87e:eb43:1345::6789", expected: "tor:3"},
// IPv6 normal.
{name: "ipv6 normal", ip: "2602:100::1", expected: "2602:100::"},
{name: "ipv6 normal 2", ip: "2602:0100::1234", expected: "2602:100::"},
{name: "ipv6 hurricane electric", ip: "2001:470:1f10:a1::2", expected: "2001:470:1000::"},
{name: "ipv6 hurricane electric 2", ip: "2001:0470:1f10:a1::2", expected: "2001:470:1000::"},
}
for i, test := range tests {
nip := net.ParseIP(test.ip)
na := btcwire.NetAddress{
Timestamp: time.Now(),
Services: btcwire.SFNodeNetwork,
IP: nip,
Port: 8333,
}
if key := addrmgr.GroupKey(&na); key != test.expected {
t.Errorf("TestGroupKey #%d (%s): unexpected group key "+
"- got '%s', want '%s'", i, test.name,
key, test.expected)
}
}
}
// 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
}
// 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 <- struct{}{} })
out:
for {
select {
// New peers connected to the server.
case p := <-s.newPeers:
s.handleAddPeerMsg(state, p)
// Disconnected peers.
case p := <-s.donePeers:
s.handleDonePeerMsg(state, p)
// Peer to ban.
case p := <-s.banPeers:
s.handleBanPeerMsg(state, p)
// New inventory to potentially be relayed to other peers.
case invMsg := <-s.relayInv:
s.handleRelayInvMsg(state, invMsg)
// Message to broadcast to all connected peers except those
// which are excluded by the message.
case bmsg := <-s.broadcast:
s.handleBroadcastMsg(state, &bmsg)
// 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)
// Shutdown the peer handler.
case <-s.quit:
// Shutdown peers.
state.forAllPeers(func(p *peer) {
p.Shutdown()
})
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 {
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 := 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
}
// 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.NetAddress().Port) !=
activeNetParams.DefaultPort && tries < 50 {
continue
}
addrStr := addrmgr.NetAddressKey(addr.NetAddress())
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 <- struct{}{}
})
}
}
s.blockManager.Stop()
s.addrManager.Stop()
s.wg.Done()
srvrLog.Tracef("Peer handler done")
}
// 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 := int32(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 = float64(p.lastPingMicros)
if p.lastPingNonce != 0 {
wait := float64(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[addrmgr.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
}
}