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p2p, p2p/discover: add signed ENR generation (#17753)

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This PR adds enode.LocalNode and integrates it into the p2p
subsystem. This new object is the keeper of the local node
record. For now, a new version of the record is produced every
time the client restarts. We'll make it smarter to avoid that in
the future.

There are a couple of other changes in this commit: discovery now
waits for all of its goroutines at shutdown and the p2p server
now closes the node database after discovery has shut down. This
fixes a leveldb crash in tests. p2p server startup is faster
because it doesn't need to wait for the external IP query
anymore.
This commit is contained in:
Felix Lange
2018-10-12 11:47:24 +02:00
committed by GitHub
parent dcae0d348b
commit 6f607de5d5
24 changed files with 979 additions and 278 deletions
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238
p2p/server.go
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@ -20,9 +20,11 @@ package p2p
import (
"bytes"
"crypto/ecdsa"
"encoding/hex"
"errors"
"fmt"
"net"
"sort"
"sync"
"sync/atomic"
"time"
@ -35,8 +37,10 @@ import (
"github.com/ethereum/go-ethereum/p2p/discover"
"github.com/ethereum/go-ethereum/p2p/discv5"
"github.com/ethereum/go-ethereum/p2p/enode"
"github.com/ethereum/go-ethereum/p2p/enr"
"github.com/ethereum/go-ethereum/p2p/nat"
"github.com/ethereum/go-ethereum/p2p/netutil"
"github.com/ethereum/go-ethereum/rlp"
)
const (
@ -160,6 +164,8 @@ type Server struct {
lock sync.Mutex // protects running
running bool
nodedb *enode.DB
localnode *enode.LocalNode
ntab discoverTable
listener net.Listener
ourHandshake *protoHandshake
@ -347,43 +353,13 @@ func (srv *Server) SubscribeEvents(ch chan *PeerEvent) event.Subscription {
// Self returns the local node's endpoint information.
func (srv *Server) Self() *enode.Node {
srv.lock.Lock()
running, listener, ntab := srv.running, srv.listener, srv.ntab
ln := srv.localnode
srv.lock.Unlock()
if !running {
if ln == nil {
return enode.NewV4(&srv.PrivateKey.PublicKey, net.ParseIP("0.0.0.0"), 0, 0)
}
return srv.makeSelf(listener, ntab)
}
func (srv *Server) makeSelf(listener net.Listener, ntab discoverTable) *enode.Node {
// If the node is running but discovery is off, manually assemble the node infos.
if ntab == nil {
addr := srv.tcpAddr(listener)
return enode.NewV4(&srv.PrivateKey.PublicKey, addr.IP, addr.Port, 0)
}
// Otherwise return the discovery node.
return ntab.Self()
}
func (srv *Server) tcpAddr(listener net.Listener) net.TCPAddr {
addr := net.TCPAddr{IP: net.IP{0, 0, 0, 0}}
if listener == nil {
return addr // Inbound connections disabled, use zero address.
}
// Otherwise inject the listener address too.
if a, ok := listener.Addr().(*net.TCPAddr); ok {
addr = *a
}
if srv.NAT != nil {
if ip, err := srv.NAT.ExternalIP(); err == nil {
addr.IP = ip
}
}
if addr.IP.IsUnspecified() {
addr.IP = net.IP{127, 0, 0, 1}
}
return addr
return ln.Node()
}
// Stop terminates the server and all active peer connections.
@ -443,7 +419,9 @@ func (srv *Server) Start() (err error) {
if srv.log == nil {
srv.log = log.New()
}
srv.log.Info("Starting P2P networking")
if srv.NoDial && srv.ListenAddr == "" {
srv.log.Warn("P2P server will be useless, neither dialing nor listening")
}
// static fields
if srv.PrivateKey == nil {
@ -466,65 +444,120 @@ func (srv *Server) Start() (err error) {
srv.peerOp = make(chan peerOpFunc)
srv.peerOpDone = make(chan struct{})
var (
conn *net.UDPConn
sconn *sharedUDPConn
realaddr *net.UDPAddr
unhandled chan discover.ReadPacket
)
if !srv.NoDiscovery || srv.DiscoveryV5 {
addr, err := net.ResolveUDPAddr("udp", srv.ListenAddr)
if err != nil {
if err := srv.setupLocalNode(); err != nil {
return err
}
if srv.ListenAddr != "" {
if err := srv.setupListening(); err != nil {
return err
}
conn, err = net.ListenUDP("udp", addr)
if err != nil {
return err
}
realaddr = conn.LocalAddr().(*net.UDPAddr)
if srv.NAT != nil {
if !realaddr.IP.IsLoopback() {
go nat.Map(srv.NAT, srv.quit, "udp", realaddr.Port, realaddr.Port, "ethereum discovery")
}
// TODO: react to external IP changes over time.
if ext, err := srv.NAT.ExternalIP(); err == nil {
realaddr = &net.UDPAddr{IP: ext, Port: realaddr.Port}
}
}
}
if err := srv.setupDiscovery(); err != nil {
return err
}
if !srv.NoDiscovery && srv.DiscoveryV5 {
unhandled = make(chan discover.ReadPacket, 100)
sconn = &sharedUDPConn{conn, unhandled}
dynPeers := srv.maxDialedConns()
dialer := newDialState(srv.localnode.ID(), srv.StaticNodes, srv.BootstrapNodes, srv.ntab, dynPeers, srv.NetRestrict)
srv.loopWG.Add(1)
go srv.run(dialer)
return nil
}
func (srv *Server) setupLocalNode() error {
// Create the devp2p handshake.
pubkey := crypto.FromECDSAPub(&srv.PrivateKey.PublicKey)
srv.ourHandshake = &protoHandshake{Version: baseProtocolVersion, Name: srv.Name, ID: pubkey[1:]}
for _, p := range srv.Protocols {
srv.ourHandshake.Caps = append(srv.ourHandshake.Caps, p.cap())
}
sort.Sort(capsByNameAndVersion(srv.ourHandshake.Caps))
// Create the local node.
db, err := enode.OpenDB(srv.Config.NodeDatabase)
if err != nil {
return err
}
srv.nodedb = db
srv.localnode = enode.NewLocalNode(db, srv.PrivateKey)
srv.localnode.SetFallbackIP(net.IP{127, 0, 0, 1})
srv.localnode.Set(capsByNameAndVersion(srv.ourHandshake.Caps))
// TODO: check conflicts
for _, p := range srv.Protocols {
for _, e := range p.Attributes {
srv.localnode.Set(e)
}
}
switch srv.NAT.(type) {
case nil:
// No NAT interface, do nothing.
case nat.ExtIP:
// ExtIP doesn't block, set the IP right away.
ip, _ := srv.NAT.ExternalIP()
srv.localnode.SetStaticIP(ip)
default:
// Ask the router about the IP. This takes a while and blocks startup,
// do it in the background.
srv.loopWG.Add(1)
go func() {
defer srv.loopWG.Done()
if ip, err := srv.NAT.ExternalIP(); err == nil {
srv.localnode.SetStaticIP(ip)
}
}()
}
return nil
}
func (srv *Server) setupDiscovery() error {
if srv.NoDiscovery && !srv.DiscoveryV5 {
return nil
}
// node table
addr, err := net.ResolveUDPAddr("udp", srv.ListenAddr)
if err != nil {
return err
}
conn, err := net.ListenUDP("udp", addr)
if err != nil {
return err
}
realaddr := conn.LocalAddr().(*net.UDPAddr)
srv.log.Debug("UDP listener up", "addr", realaddr)
if srv.NAT != nil {
if !realaddr.IP.IsLoopback() {
go nat.Map(srv.NAT, srv.quit, "udp", realaddr.Port, realaddr.Port, "ethereum discovery")
}
}
srv.localnode.SetFallbackUDP(realaddr.Port)
// Discovery V4
var unhandled chan discover.ReadPacket
var sconn *sharedUDPConn
if !srv.NoDiscovery {
cfg := discover.Config{
PrivateKey: srv.PrivateKey,
AnnounceAddr: realaddr,
NodeDBPath: srv.NodeDatabase,
NetRestrict: srv.NetRestrict,
Bootnodes: srv.BootstrapNodes,
Unhandled: unhandled,
if srv.DiscoveryV5 {
unhandled = make(chan discover.ReadPacket, 100)
sconn = &sharedUDPConn{conn, unhandled}
}
ntab, err := discover.ListenUDP(conn, cfg)
cfg := discover.Config{
PrivateKey: srv.PrivateKey,
NetRestrict: srv.NetRestrict,
Bootnodes: srv.BootstrapNodes,
Unhandled: unhandled,
}
ntab, err := discover.ListenUDP(conn, srv.localnode, cfg)
if err != nil {
return err
}
srv.ntab = ntab
}
// Discovery V5
if srv.DiscoveryV5 {
var (
ntab *discv5.Network
err error
)
var ntab *discv5.Network
var err error
if sconn != nil {
ntab, err = discv5.ListenUDP(srv.PrivateKey, sconn, realaddr, "", srv.NetRestrict) //srv.NodeDatabase)
ntab, err = discv5.ListenUDP(srv.PrivateKey, sconn, "", srv.NetRestrict)
} else {
ntab, err = discv5.ListenUDP(srv.PrivateKey, conn, realaddr, "", srv.NetRestrict) //srv.NodeDatabase)
ntab, err = discv5.ListenUDP(srv.PrivateKey, conn, "", srv.NetRestrict)
}
if err != nil {
return err
@ -534,32 +567,10 @@ func (srv *Server) Start() (err error) {
}
srv.DiscV5 = ntab
}
dynPeers := srv.maxDialedConns()
dialer := newDialState(srv.StaticNodes, srv.BootstrapNodes, srv.ntab, dynPeers, srv.NetRestrict)
// handshake
pubkey := crypto.FromECDSAPub(&srv.PrivateKey.PublicKey)
srv.ourHandshake = &protoHandshake{Version: baseProtocolVersion, Name: srv.Name, ID: pubkey[1:]}
for _, p := range srv.Protocols {
srv.ourHandshake.Caps = append(srv.ourHandshake.Caps, p.cap())
}
// listen/dial
if srv.ListenAddr != "" {
if err := srv.startListening(); err != nil {
return err
}
}
if srv.NoDial && srv.ListenAddr == "" {
srv.log.Warn("P2P server will be useless, neither dialing nor listening")
}
srv.loopWG.Add(1)
go srv.run(dialer)
return nil
}
func (srv *Server) startListening() error {
func (srv *Server) setupListening() error {
// Launch the TCP listener.
listener, err := net.Listen("tcp", srv.ListenAddr)
if err != nil {
@ -568,8 +579,11 @@ func (srv *Server) startListening() error {
laddr := listener.Addr().(*net.TCPAddr)
srv.ListenAddr = laddr.String()
srv.listener = listener
srv.localnode.Set(enr.TCP(laddr.Port))
srv.loopWG.Add(1)
go srv.listenLoop()
// Map the TCP listening port if NAT is configured.
if !laddr.IP.IsLoopback() && srv.NAT != nil {
srv.loopWG.Add(1)
@ -589,7 +603,10 @@ type dialer interface {
}
func (srv *Server) run(dialstate dialer) {
srv.log.Info("Started P2P networking", "self", srv.localnode.Node())
defer srv.loopWG.Done()
defer srv.nodedb.Close()
var (
peers = make(map[enode.ID]*Peer)
inboundCount = 0
@ -781,7 +798,7 @@ func (srv *Server) encHandshakeChecks(peers map[enode.ID]*Peer, inboundCount int
return DiscTooManyPeers
case peers[c.node.ID()] != nil:
return DiscAlreadyConnected
case c.node.ID() == srv.Self().ID():
case c.node.ID() == srv.localnode.ID():
return DiscSelf
default:
return nil
@ -802,15 +819,11 @@ func (srv *Server) maxDialedConns() int {
return srv.MaxPeers / r
}
type tempError interface {
Temporary() bool
}
// listenLoop runs in its own goroutine and accepts
// inbound connections.
func (srv *Server) listenLoop() {
defer srv.loopWG.Done()
srv.log.Info("RLPx listener up", "self", srv.Self())
srv.log.Debug("TCP listener up", "addr", srv.listener.Addr())
tokens := defaultMaxPendingPeers
if srv.MaxPendingPeers > 0 {
@ -831,7 +844,7 @@ func (srv *Server) listenLoop() {
)
for {
fd, err = srv.listener.Accept()
if tempErr, ok := err.(tempError); ok && tempErr.Temporary() {
if netutil.IsTemporaryError(err) {
srv.log.Debug("Temporary read error", "err", err)
continue
} else if err != nil {
@ -864,10 +877,6 @@ func (srv *Server) listenLoop() {
// as a peer. It returns when the connection has been added as a peer
// or the handshakes have failed.
func (srv *Server) SetupConn(fd net.Conn, flags connFlag, dialDest *enode.Node) error {
self := srv.Self()
if self == nil {
return errors.New("shutdown")
}
c := &conn{fd: fd, transport: srv.newTransport(fd), flags: flags, cont: make(chan error)}
err := srv.setupConn(c, flags, dialDest)
if err != nil {
@ -1003,6 +1012,7 @@ type NodeInfo struct {
ID string `json:"id"` // Unique node identifier (also the encryption key)
Name string `json:"name"` // Name of the node, including client type, version, OS, custom data
Enode string `json:"enode"` // Enode URL for adding this peer from remote peers
ENR string `json:"enr"` // Ethereum Node Record
IP string `json:"ip"` // IP address of the node
Ports struct {
Discovery int `json:"discovery"` // UDP listening port for discovery protocol
@ -1014,9 +1024,8 @@ type NodeInfo struct {
// NodeInfo gathers and returns a collection of metadata known about the host.
func (srv *Server) NodeInfo() *NodeInfo {
node := srv.Self()
// Gather and assemble the generic node infos
node := srv.Self()
info := &NodeInfo{
Name: srv.Name,
Enode: node.String(),
@ -1027,6 +1036,9 @@ func (srv *Server) NodeInfo() *NodeInfo {
}
info.Ports.Discovery = node.UDP()
info.Ports.Listener = node.TCP()
if enc, err := rlp.EncodeToBytes(node.Record()); err == nil {
info.ENR = "0x" + hex.EncodeToString(enc)
}
// Gather all the running protocol infos (only once per protocol type)
for _, proto := range srv.Protocols {