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Merge pull request #691 from fjl/discovery-fixes 

p2p: a bunch of fixes
This commit is contained in:
Jeffrey Wilcke 2015-04-10 17:59:32 +02:00
parent fc1d1f9afd c5332537f5
commit 92fbb61625
8 changed files with 360 additions and 189 deletions
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15
p2p/discover/udp.go
View File

@ -335,7 +335,7 @@ func (t *udp) send(toaddr *net.UDPAddr, ptype byte, req interface{}) error {
if err != nil {
return err
}
glog.V(logger.Detail).Infof(">>> %v %T %v\n", toaddr, req, req)
glog.V(logger.Detail).Infof(">>> %v %T\n", toaddr, req)
if _, err = t.conn.WriteToUDP(packet, toaddr); err != nil {
glog.V(logger.Detail).Infoln("UDP send failed:", err)
}
@ -378,12 +378,11 @@ func (t *udp) readLoop() {
glog.V(logger.Debug).Infof("Bad packet from %v: %v\n", from, err)
continue
}
glog.V(logger.Detail).Infof("<<< %v %T %v\n", from, packet, packet)
go func() {
if err := packet.handle(t, from, fromID, hash); err != nil {
glog.V(logger.Debug).Infof("error handling %T from %v: %v", packet, from, err)
}
}()
status := "ok"
if err := packet.handle(t, from, fromID, hash); err != nil {
status = err.Error()
}
glog.V(logger.Detail).Infof("<<< %v %T: %s\n", from, packet, status)
}
}
@ -430,7 +429,7 @@ func (req *ping) handle(t *udp, from *net.UDPAddr, fromID NodeID, mac []byte) er
})
if !t.handleReply(fromID, pingPacket, req) {
// Note: we're ignoring the provided IP address right now
t.bond(true, fromID, from, req.Port)
go t.bond(true, fromID, from, req.Port)
}
return nil
}

68
p2p/handshake.go
View File

@ -68,50 +68,61 @@ type protoHandshake struct {
// setupConn starts a protocol session on the given connection.
// It runs the encryption handshake and the protocol handshake.
// If dial is non-nil, the connection the local node is the initiator.
func setupConn(fd net.Conn, prv *ecdsa.PrivateKey, our *protoHandshake, dial *discover.Node) (*conn, error) {
// If atcap is true, the connection will be disconnected with DiscTooManyPeers
// after the key exchange.
func setupConn(fd net.Conn, prv *ecdsa.PrivateKey, our *protoHandshake, dial *discover.Node, atcap bool) (*conn, error) {
if dial == nil {
return setupInboundConn(fd, prv, our)
return setupInboundConn(fd, prv, our, atcap)
} else {
return setupOutboundConn(fd, prv, our, dial)
return setupOutboundConn(fd, prv, our, dial, atcap)
}
}
func setupInboundConn(fd net.Conn, prv *ecdsa.PrivateKey, our *protoHandshake) (*conn, error) {
func setupInboundConn(fd net.Conn, prv *ecdsa.PrivateKey, our *protoHandshake, atcap bool) (*conn, error) {
secrets, err := receiverEncHandshake(fd, prv, nil)
if err != nil {
return nil, fmt.Errorf("encryption handshake failed: %v", err)
}
// Run the protocol handshake using authenticated messages.
rw := newRlpxFrameRW(fd, secrets)
rhs, err := readProtocolHandshake(rw, our)
if atcap {
SendItems(rw, discMsg, DiscTooManyPeers)
return nil, errors.New("we have too many peers")
}
// Run the protocol handshake using authenticated messages.
rhs, err := readProtocolHandshake(rw, secrets.RemoteID, our)
if err != nil {
return nil, err
}
if rhs.ID != secrets.RemoteID {
return nil, errors.New("node ID in protocol handshake does not match encryption handshake")
}
// TODO: validate that handshake node ID matches
if err := Send(rw, handshakeMsg, our); err != nil {
return nil, fmt.Errorf("protocol write error: %v", err)
return nil, fmt.Errorf("protocol handshake write error: %v", err)
}
return &conn{rw, rhs}, nil
}
func setupOutboundConn(fd net.Conn, prv *ecdsa.PrivateKey, our *protoHandshake, dial *discover.Node) (*conn, error) {
func setupOutboundConn(fd net.Conn, prv *ecdsa.PrivateKey, our *protoHandshake, dial *discover.Node, atcap bool) (*conn, error) {
secrets, err := initiatorEncHandshake(fd, prv, dial.ID, nil)
if err != nil {
return nil, fmt.Errorf("encryption handshake failed: %v", err)
}
// Run the protocol handshake using authenticated messages.
rw := newRlpxFrameRW(fd, secrets)
if err := Send(rw, handshakeMsg, our); err != nil {
return nil, fmt.Errorf("protocol write error: %v", err)
if atcap {
SendItems(rw, discMsg, DiscTooManyPeers)
return nil, errors.New("we have too many peers")
}
rhs, err := readProtocolHandshake(rw, our)
// Run the protocol handshake using authenticated messages.
//
// Note that even though writing the handshake is first, we prefer
// returning the handshake read error. If the remote side
// disconnects us early with a valid reason, we should return it
// as the error so it can be tracked elsewhere.
werr := make(chan error)
go func() { werr <- Send(rw, handshakeMsg, our) }()
rhs, err := readProtocolHandshake(rw, secrets.RemoteID, our)
if err != nil {
return nil, fmt.Errorf("protocol handshake read error: %v", err)
return nil, err
}
if err := <-werr; err != nil {
return nil, fmt.Errorf("protocol handshake write error: %v", err)
}
if rhs.ID != dial.ID {
return nil, errors.New("dialed node id mismatch")
@ -398,18 +409,17 @@ func xor(one, other []byte) (xor []byte) {
return xor
}
func readProtocolHandshake(r MsgReader, our *protoHandshake) (*protoHandshake, error) {
// read and handle remote handshake
msg, err := r.ReadMsg()
func readProtocolHandshake(rw MsgReadWriter, wantID discover.NodeID, our *protoHandshake) (*protoHandshake, error) {
msg, err := rw.ReadMsg()
if err != nil {
return nil, err
}
if msg.Code == discMsg {
// disconnect before protocol handshake is valid according to the
// spec and we send it ourself if Server.addPeer fails.
var reason DiscReason
var reason [1]DiscReason
rlp.Decode(msg.Payload, &reason)
return nil, discRequestedError(reason)
return nil, reason[0]
}
if msg.Code != handshakeMsg {
return nil, fmt.Errorf("expected handshake, got %x", msg.Code)
@ -423,10 +433,16 @@ func readProtocolHandshake(r MsgReader, our *protoHandshake) (*protoHandshake, e
}
// validate handshake info
if hs.Version != our.Version {
return nil, newPeerError(errP2PVersionMismatch, "required version %d, received %d\n", baseProtocolVersion, hs.Version)
SendItems(rw, discMsg, DiscIncompatibleVersion)
return nil, fmt.Errorf("required version %d, received %d\n", baseProtocolVersion, hs.Version)
}
if (hs.ID == discover.NodeID{}) {
return nil, newPeerError(errPubkeyInvalid, "missing")
SendItems(rw, discMsg, DiscInvalidIdentity)
return nil, errors.New("invalid public key in handshake")
}
if hs.ID != wantID {
SendItems(rw, discMsg, DiscUnexpectedIdentity)
return nil, errors.New("handshake node ID does not match encryption handshake")
}
return &hs, nil
}

4
p2p/handshake_test.go
View File

@ -143,7 +143,7 @@ func TestSetupConn(t *testing.T) {
done := make(chan struct{})
go func() {
defer close(done)
conn0, err := setupConn(fd0, prv0, hs0, node1)
conn0, err := setupConn(fd0, prv0, hs0, node1, false)
if err != nil {
t.Errorf("outbound side error: %v", err)
return
@ -156,7 +156,7 @@ func TestSetupConn(t *testing.T) {
}
}()
conn1, err := setupConn(fd1, prv1, hs1, nil)
conn1, err := setupConn(fd1, prv1, hs1, nil, false)
if err != nil {
t.Fatalf("inbound side error: %v", err)
}

140
p2p/peer.go
View File

@ -44,7 +44,7 @@ type Peer struct {
rw *conn
running map[string]*protoRW
protoWG sync.WaitGroup
wg sync.WaitGroup
protoErr chan error
closed chan struct{}
disc chan DiscReason
@ -102,58 +102,50 @@ func (p *Peer) String() string {
func newPeer(fd net.Conn, conn *conn, protocols []Protocol) *Peer {
logtag := fmt.Sprintf("Peer %.8x %v", conn.ID[:], fd.RemoteAddr())
protomap := matchProtocols(protocols, conn.Caps, conn)
p := &Peer{
Logger: logger.NewLogger(logtag),
conn: fd,
rw: conn,
running: matchProtocols(protocols, conn.Caps, conn),
running: protomap,
disc: make(chan DiscReason),
protoErr: make(chan error),
protoErr: make(chan error, len(protomap)+1), // protocols + pingLoop
closed: make(chan struct{}),
}
return p
}
func (p *Peer) run() DiscReason {
var readErr = make(chan error, 1)
defer p.closeProtocols()
defer close(p.closed)
readErr := make(chan error, 1)
p.wg.Add(2)
go p.readLoop(readErr)
go p.pingLoop()
p.startProtocols()
go func() { readErr <- p.readLoop() }()
ping := time.NewTicker(pingInterval)
defer ping.Stop()
// Wait for an error or disconnect.
var reason DiscReason
loop:
for {
select {
case <-ping.C:
go func() {
if err := SendItems(p.rw, pingMsg); err != nil {
p.protoErr <- err
return
}
}()
case err := <-readErr:
// We rely on protocols to abort if there is a write error. It
// might be more robust to handle them here as well.
p.DebugDetailf("Read error: %v\n", err)
p.conn.Close()
return DiscNetworkError
case err := <-p.protoErr:
reason = discReasonForError(err)
break loop
case reason = <-p.disc:
break loop
select {
case err := <-readErr:
if r, ok := err.(DiscReason); ok {
reason = r
break
}
// Note: We rely on protocols to abort if there is a write
// error. It might be more robust to handle them here as well.
p.DebugDetailf("Read error: %v\n", err)
p.conn.Close()
reason = DiscNetworkError
case err := <-p.protoErr:
reason = discReasonForError(err)
case reason = <-p.disc:
}
p.politeDisconnect(reason)
// Wait for readLoop. It will end because conn is now closed.
<-readErr
close(p.closed)
p.wg.Wait()
if reason != DiscNetworkError {
p.politeDisconnect(reason)
}
p.Debugf("Disconnected: %v\n", reason)
return reason
}
@ -174,18 +166,36 @@ func (p *Peer) politeDisconnect(reason DiscReason) {
p.conn.Close()
}
func (p *Peer) readLoop() error {
func (p *Peer) pingLoop() {
ping := time.NewTicker(pingInterval)
defer p.wg.Done()
defer ping.Stop()
for {
p.conn.SetDeadline(time.Now().Add(frameReadTimeout))
msg, err := p.rw.ReadMsg()
if err != nil {
return err
}
if err = p.handle(msg); err != nil {
return err
select {
case <-ping.C:
if err := SendItems(p.rw, pingMsg); err != nil {
p.protoErr <- err
return
}
case <-p.closed:
return
}
}
}
func (p *Peer) readLoop(errc chan<- error) {
defer p.wg.Done()
for {
msg, err := p.rw.ReadMsg()
if err != nil {
errc <- err
return
}
if err = p.handle(msg); err != nil {
errc <- err
return
}
}
return nil
}
func (p *Peer) handle(msg Msg) error {
@ -195,12 +205,11 @@ func (p *Peer) handle(msg Msg) error {
go SendItems(p.rw, pongMsg)
case msg.Code == discMsg:
var reason [1]DiscReason
// no need to discard or for error checking, we'll close the
// connection after this.
// This is the last message. We don't need to discard or
// check errors because, the connection will be closed after it.
rlp.Decode(msg.Payload, &reason)
p.Debugf("Disconnect requested: %v\n", reason[0])
p.Disconnect(DiscRequested)
return discRequestedError(reason[0])
return DiscRequested
case msg.Code < baseProtocolLength:
// ignore other base protocol messages
return msg.Discard()
@ -210,7 +219,12 @@ func (p *Peer) handle(msg Msg) error {
if err != nil {
return fmt.Errorf("msg code out of range: %v", msg.Code)
}
proto.in <- msg
select {
case proto.in <- msg:
return nil
case <-p.closed:
return io.EOF
}
}
return nil
}
@ -234,10 +248,11 @@ outer:
}
func (p *Peer) startProtocols() {
p.wg.Add(len(p.running))
for _, proto := range p.running {
proto := proto
proto.closed = p.closed
p.DebugDetailf("Starting protocol %s/%d\n", proto.Name, proto.Version)
p.protoWG.Add(1)
go func() {
err := proto.Run(p, proto)
if err == nil {
@ -246,11 +261,8 @@ func (p *Peer) startProtocols() {
} else {
p.DebugDetailf("Protocol %s/%d error: %v\n", proto.Name, proto.Version, err)
}
select {
case p.protoErr <- err:
case <-p.closed:
}
p.protoWG.Done()
p.protoErr <- err
p.wg.Done()
}()
}
}
@ -266,13 +278,6 @@ func (p *Peer) getProto(code uint64) (*protoRW, error) {
return nil, newPeerError(errInvalidMsgCode, "%d", code)
}
func (p *Peer) closeProtocols() {
for _, p := range p.running {
close(p.in)
}
p.protoWG.Wait()
}
// writeProtoMsg sends the given message on behalf of the given named protocol.
// this exists because of Server.Broadcast.
func (p *Peer) writeProtoMsg(protoName string, msg Msg) error {
@ -289,8 +294,8 @@ func (p *Peer) writeProtoMsg(protoName string, msg Msg) error {
type protoRW struct {
Protocol
in chan Msg
closed <-chan struct{}
offset uint64
w MsgWriter
}
@ -304,10 +309,11 @@ func (rw *protoRW) WriteMsg(msg Msg) error {
}
func (rw *protoRW) ReadMsg() (Msg, error) {
msg, ok := <-rw.in
if !ok {
return msg, io.EOF
select {
case msg := <-rw.in:
msg.Code -= rw.offset
return msg, nil
case <-rw.closed:
return Msg{}, io.EOF
}
msg.Code -= rw.offset
return msg, nil
}

10
p2p/peer_error.go
View File

@ -98,15 +98,13 @@ func (d DiscReason) String() string {
return discReasonToString[d]
}
type discRequestedError DiscReason
func (err discRequestedError) Error() string {
return fmt.Sprintf("disconnect requested: %v", DiscReason(err))
func (d DiscReason) Error() string {
return d.String()
}
func discReasonForError(err error) DiscReason {
if reason, ok := err.(discRequestedError); ok {
return DiscReason(reason)
if reason, ok := err.(DiscReason); ok {
return reason
}
peerError, ok := err.(*peerError)
if !ok {

74
p2p/peer_test.go
View File

@ -2,8 +2,9 @@ package p2p
import (
"bytes"
"errors"
"fmt"
"io"
"math/rand"
"net"
"reflect"
"testing"
@ -27,7 +28,7 @@ var discard = Protocol{
},
}
func testPeer(protos []Protocol) (io.Closer, *conn, *Peer, <-chan DiscReason) {
func testPeer(protos []Protocol) (func(), *conn, *Peer, <-chan DiscReason) {
fd1, _ := net.Pipe()
hs1 := &protoHandshake{ID: randomID(), Version: baseProtocolVersion}
hs2 := &protoHandshake{ID: randomID(), Version: baseProtocolVersion}
@ -41,7 +42,11 @@ func testPeer(protos []Protocol) (io.Closer, *conn, *Peer, <-chan DiscReason) {
errc := make(chan DiscReason, 1)
go func() { errc <- peer.run() }()
return p1, &conn{p2, hs2}, peer, errc
closer := func() {
p1.Close()
fd1.Close()
}
return closer, &conn{p2, hs2}, peer, errc
}
func TestPeerProtoReadMsg(t *testing.T) {
@ -67,7 +72,7 @@ func TestPeerProtoReadMsg(t *testing.T) {
}
closer, rw, _, errc := testPeer([]Protocol{proto})
defer closer.Close()
defer closer()
Send(rw, baseProtocolLength+2, []uint{1})
Send(rw, baseProtocolLength+3, []uint{2})
@ -99,7 +104,7 @@ func TestPeerProtoEncodeMsg(t *testing.T) {
},
}
closer, rw, _, _ := testPeer([]Protocol{proto})
defer closer.Close()
defer closer()
if err := ExpectMsg(rw, 17, []string{"foo", "bar"}); err != nil {
t.Error(err)
@ -110,7 +115,7 @@ func TestPeerWriteForBroadcast(t *testing.T) {
defer testlog(t).detach()
closer, rw, peer, peerErr := testPeer([]Protocol{discard})
defer closer.Close()
defer closer()
emptymsg := func(code uint64) Msg {
return Msg{Code: code, Size: 0, Payload: bytes.NewReader(nil)}
@ -150,7 +155,7 @@ func TestPeerPing(t *testing.T) {
defer testlog(t).detach()
closer, rw, _, _ := testPeer(nil)
defer closer.Close()
defer closer()
if err := SendItems(rw, pingMsg); err != nil {
t.Fatal(err)
}
@ -163,19 +168,70 @@ func TestPeerDisconnect(t *testing.T) {
defer testlog(t).detach()
closer, rw, _, disc := testPeer(nil)
defer closer.Close()
defer closer()
if err := SendItems(rw, discMsg, DiscQuitting); err != nil {
t.Fatal(err)
}
if err := ExpectMsg(rw, discMsg, []interface{}{DiscRequested}); err != nil {
t.Error(err)
}
closer.Close() // make test end faster
closer()
if reason := <-disc; reason != DiscRequested {
t.Errorf("run returned wrong reason: got %v, want %v", reason, DiscRequested)
}
}
// This test is supposed to verify that Peer can reliably handle
// multiple causes of disconnection occurring at the same time.
func TestPeerDisconnectRace(t *testing.T) {
defer testlog(t).detach()
maybe := func() bool { return rand.Intn(1) == 1 }
for i := 0; i < 1000; i++ {
protoclose := make(chan error)
protodisc := make(chan DiscReason)
closer, rw, p, disc := testPeer([]Protocol{
{
Name: "closereq",
Run: func(p *Peer, rw MsgReadWriter) error { return <-protoclose },
Length: 1,
},
{
Name: "disconnect",
Run: func(p *Peer, rw MsgReadWriter) error { p.Disconnect(<-protodisc); return nil },
Length: 1,
},
})
// Simulate incoming messages.
go SendItems(rw, baseProtocolLength+1)
go SendItems(rw, baseProtocolLength+2)
// Close the network connection.
go closer()
// Make protocol "closereq" return.
protoclose <- errors.New("protocol closed")
// Make protocol "disconnect" call peer.Disconnect
protodisc <- DiscAlreadyConnected
// In some cases, simulate something else calling peer.Disconnect.
if maybe() {
go p.Disconnect(DiscInvalidIdentity)
}
// In some cases, simulate remote requesting a disconnect.
if maybe() {
go SendItems(rw, discMsg, DiscQuitting)
}
select {
case <-disc:
case <-time.After(2 * time.Second):
// Peer.run should return quickly. If it doesn't the Peer
// goroutines are probably deadlocked. Call panic in order to
// show the stacks.
panic("Peer.run took to long to return.")
}
}
}
func TestNewPeer(t *testing.T) {
name := "nodename"
caps := []Cap{{"foo", 2}, {"bar", 3}}

180
p2p/server.go
View File

@ -3,6 +3,7 @@ package p2p
import (
"bytes"
"crypto/ecdsa"
"crypto/rand"
"errors"
"fmt"
"net"
@ -20,6 +21,11 @@ const (
defaultDialTimeout = 10 * time.Second
refreshPeersInterval = 30 * time.Second
// This is the maximum number of inbound connection
// that are allowed to linger between 'accepted' and
// 'added as peer'.
maxAcceptConns = 50
// total timeout for encryption handshake and protocol
// handshake in both directions.
handshakeTimeout = 5 * time.Second
@ -85,12 +91,12 @@ type Server struct {
ourHandshake *protoHandshake
lock sync.RWMutex
running bool
listener net.Listener
peers map[discover.NodeID]*Peer
lock sync.RWMutex // protects running and peers
running bool
peers map[discover.NodeID]*Peer
ntab *discover.Table
ntab *discover.Table
listener net.Listener
quit chan struct{}
loopWG sync.WaitGroup // {dial,listen,nat}Loop
@ -98,7 +104,7 @@ type Server struct {
peerConnect chan *discover.Node
}
type setupFunc func(net.Conn, *ecdsa.PrivateKey, *protoHandshake, *discover.Node) (*conn, error)
type setupFunc func(net.Conn, *ecdsa.PrivateKey, *protoHandshake, *discover.Node, bool) (*conn, error)
type newPeerHook func(*Peer)
// Peers returns all connected peers.
@ -260,62 +266,94 @@ func (srv *Server) Stop() {
srv.peerWG.Wait()
}
// Self returns the local node's endpoint information.
func (srv *Server) Self() *discover.Node {
return srv.ntab.Self()
}
// main loop for adding connections via listening
func (srv *Server) listenLoop() {
defer srv.loopWG.Done()
// This channel acts as a semaphore limiting
// active inbound connections that are lingering pre-handshake.
// If all slots are taken, no further connections are accepted.
slots := make(chan struct{}, maxAcceptConns)
for i := 0; i < maxAcceptConns; i++ {
slots <- struct{}{}
}
glog.V(logger.Info).Infoln("Listening on", srv.listener.Addr())
for {
<-slots
conn, err := srv.listener.Accept()
if err != nil {
return
}
glog.V(logger.Debug).Infof("Accepted conn %v\n", conn.RemoteAddr())
srv.peerWG.Add(1)
go srv.startPeer(conn, nil)
go func() {
srv.startPeer(conn, nil)
slots <- struct{}{}
}()
}
}
func (srv *Server) dialLoop() {
var (
dialed = make(chan *discover.Node)
dialing = make(map[discover.NodeID]bool)
findresults = make(chan []*discover.Node)
refresh = time.NewTimer(0)
)
defer srv.loopWG.Done()
refresh := time.NewTicker(refreshPeersInterval)
defer refresh.Stop()
// TODO: maybe limit number of active dials
dial := func(dest *discover.Node) {
// Don't dial nodes that would fail the checks in addPeer.
// This is important because the connection handshake is a lot
// of work and we'd rather avoid doing that work for peers
// that can't be added.
srv.lock.RLock()
ok, _ := srv.checkPeer(dest.ID)
srv.lock.RUnlock()
if !ok || dialing[dest.ID] {
return
}
dialing[dest.ID] = true
srv.peerWG.Add(1)
go func() {
srv.dialNode(dest)
dialed <- dest
}()
}
srv.ntab.Bootstrap(srv.BootstrapNodes)
go srv.findPeers()
dialed := make(chan *discover.Node)
dialing := make(map[discover.NodeID]bool)
// TODO: limit number of active dials
// TODO: ensure only one findPeers goroutine is running
// TODO: pause findPeers when we're at capacity
for {
select {
case <-refresh.C:
go srv.findPeers()
case dest := <-srv.peerConnect:
// avoid dialing nodes that are already connected.
// there is another check for this in addPeer,
// which runs after the handshake.
srv.lock.Lock()
_, isconnected := srv.peers[dest.ID]
srv.lock.Unlock()
if isconnected || dialing[dest.ID] || dest.ID == srv.Self().ID {
continue
// Grab some nodes to connect to if we're not at capacity.
srv.lock.RLock()
needpeers := len(srv.peers) < srv.MaxPeers
srv.lock.RUnlock()
if needpeers {
go func() {
var target discover.NodeID
rand.Read(target[:])
findresults <- srv.ntab.Lookup(target)
}()
refresh.Stop()
}
dialing[dest.ID] = true
srv.peerWG.Add(1)
go func() {
srv.dialNode(dest)
// at this point, the peer has been added
// or discarded. either way, we're not dialing it anymore.
dialed <- dest
}()
case dest := <-srv.peerConnect:
dial(dest)
case dests := <-findresults:
for _, dest := range dests {
dial(dest)
}
refresh.Reset(refreshPeersInterval)
case dest := <-dialed:
delete(dialing, dest.ID)
@ -331,44 +369,34 @@ func (srv *Server) dialNode(dest *discover.Node) {
glog.V(logger.Debug).Infof("Dialing %v\n", dest)
conn, err := srv.Dialer.Dial("tcp", addr.String())
if err != nil {
// dialLoop adds to the wait group counter when launching
// dialNode, so we need to count it down again. startPeer also
// does that when an error occurs.
srv.peerWG.Done()
glog.V(logger.Detail).Infof("dial error: %v", err)
return
}
srv.startPeer(conn, dest)
}
func (srv *Server) Self() *discover.Node {
return srv.ntab.Self()
}
func (srv *Server) findPeers() {
far := srv.Self().ID
for i := range far {
far[i] = ^far[i]
}
closeToSelf := srv.ntab.Lookup(srv.Self().ID)
farFromSelf := srv.ntab.Lookup(far)
for i := 0; i < len(closeToSelf) || i < len(farFromSelf); i++ {
if i < len(closeToSelf) {
srv.peerConnect <- closeToSelf[i]
}
if i < len(farFromSelf) {
srv.peerConnect <- farFromSelf[i]
}
}
}
func (srv *Server) startPeer(fd net.Conn, dest *discover.Node) {
// TODO: handle/store session token
// Run setupFunc, which should create an authenticated connection
// and run the capability exchange. Note that any early error
// returns during that exchange need to call peerWG.Done because
// the callers of startPeer added the peer to the wait group already.
fd.SetDeadline(time.Now().Add(handshakeTimeout))
conn, err := srv.setupFunc(fd, srv.PrivateKey, srv.ourHandshake, dest)
srv.lock.RLock()
atcap := len(srv.peers) == srv.MaxPeers
srv.lock.RUnlock()
conn, err := srv.setupFunc(fd, srv.PrivateKey, srv.ourHandshake, dest, atcap)
if err != nil {
fd.Close()
glog.V(logger.Debug).Infof("Handshake with %v failed: %v", fd.RemoteAddr(), err)
srv.peerWG.Done()
return
}
conn.MsgReadWriter = &netWrapper{
wrapped: conn.MsgReadWriter,
conn: fd, rtimeout: frameReadTimeout, wtimeout: frameWriteTimeout,
@ -377,26 +405,30 @@ func (srv *Server) startPeer(fd net.Conn, dest *discover.Node) {
if ok, reason := srv.addPeer(conn.ID, p); !ok {
glog.V(logger.Detail).Infof("Not adding %v (%v)\n", p, reason)
p.politeDisconnect(reason)
srv.peerWG.Done()
return
}
// The handshakes are done and it passed all checks.
// Spawn the Peer loops.
go srv.runPeer(p)
}
func (srv *Server) runPeer(p *Peer) {
glog.V(logger.Debug).Infof("Added %v\n", p)
srvjslog.LogJson(&logger.P2PConnected{
RemoteId: fmt.Sprintf("%x", conn.ID[:]),
RemoteAddress: fd.RemoteAddr().String(),
RemoteVersionString: conn.Name,
RemoteId: p.ID().String(),
RemoteAddress: p.RemoteAddr().String(),
RemoteVersionString: p.Name(),
NumConnections: srv.PeerCount(),
})
if srv.newPeerHook != nil {
srv.newPeerHook(p)
}
discreason := p.run()
srv.removePeer(p)
glog.V(logger.Debug).Infof("Removed %v (%v)\n", p, discreason)
srvjslog.LogJson(&logger.P2PDisconnected{
RemoteId: fmt.Sprintf("%x", conn.ID[:]),
RemoteId: p.ID().String(),
NumConnections: srv.PeerCount(),
})
}
@ -404,6 +436,14 @@ func (srv *Server) startPeer(fd net.Conn, dest *discover.Node) {
func (srv *Server) addPeer(id discover.NodeID, p *Peer) (bool, DiscReason) {
srv.lock.Lock()
defer srv.lock.Unlock()
if ok, reason := srv.checkPeer(id); !ok {
return false, reason
}
srv.peers[id] = p
return true, 0
}
func (srv *Server) checkPeer(id discover.NodeID) (bool, DiscReason) {
switch {
case !srv.running:
return false, DiscQuitting
@ -413,9 +453,9 @@ func (srv *Server) addPeer(id discover.NodeID, p *Peer) (bool, DiscReason) {
return false, DiscAlreadyConnected
case id == srv.Self().ID:
return false, DiscSelf
default:
return true, 0
}
srv.peers[id] = p
return true, 0
}
func (srv *Server) removePeer(p *Peer) {

58
p2p/server_test.go
View File

@ -22,7 +22,7 @@ func startTestServer(t *testing.T, pf newPeerHook) *Server {
ListenAddr: "127.0.0.1:0",
PrivateKey: newkey(),
newPeerHook: pf,
setupFunc: func(fd net.Conn, prv *ecdsa.PrivateKey, our *protoHandshake, dial *discover.Node) (*conn, error) {
setupFunc: func(fd net.Conn, prv *ecdsa.PrivateKey, our *protoHandshake, dial *discover.Node, atcap bool) (*conn, error) {
id := randomID()
rw := newRlpxFrameRW(fd, secrets{
MAC: zero16,
@ -163,6 +163,62 @@ func TestServerBroadcast(t *testing.T) {
}
}
// This test checks that connections are disconnected
// just after the encryption handshake when the server is
// at capacity.
//
// It also serves as a light-weight integration test.
func TestServerDisconnectAtCap(t *testing.T) {
defer testlog(t).detach()
started := make(chan *Peer)
srv := &Server{
ListenAddr: "127.0.0.1:0",
PrivateKey: newkey(),
MaxPeers: 10,
NoDial: true,
// This hook signals that the peer was actually started. We
// need to wait for the peer to be started before dialing the
// next connection to get a deterministic peer count.
newPeerHook: func(p *Peer) { started <- p },
}
if err := srv.Start(); err != nil {
t.Fatal(err)
}
defer srv.Stop()
nconns := srv.MaxPeers + 1
dialer := &net.Dialer{Deadline: time.Now().Add(3 * time.Second)}
for i := 0; i < nconns; i++ {
conn, err := dialer.Dial("tcp", srv.ListenAddr)
if err != nil {
t.Fatalf("conn %d: dial error: %v", i, err)
}
// Close the connection when the test ends, before
// shutting down the server.
defer conn.Close()
// Run the handshakes just like a real peer would.
key := newkey()
hs := &protoHandshake{Version: baseProtocolVersion, ID: discover.PubkeyID(&key.PublicKey)}
_, err = setupConn(conn, key, hs, srv.Self(), false)
if i == nconns-1 {
// When handling the last connection, the server should
// disconnect immediately instead of running the protocol
// handshake.
if err != DiscTooManyPeers {
t.Errorf("conn %d: got error %q, expected %q", i, err, DiscTooManyPeers)
}
} else {
// For all earlier connections, the handshake should go through.
if err != nil {
t.Fatalf("conn %d: unexpected error: %v", i, err)
}
// Wait for runPeer to be started.
<-started
}
}
}
func newkey() *ecdsa.PrivateKey {
key, err := crypto.GenerateKey()
if err != nil {