status-go/vendor/github.com/libp2p/go-libp2p/p2p/protocol/identify/id.go

805 lines
22 KiB
Go

package identify
import (
"context"
"fmt"
"io"
"runtime/debug"
"sync"
"time"
ic "github.com/libp2p/go-libp2p-core/crypto"
"github.com/libp2p/go-libp2p-core/event"
"github.com/libp2p/go-libp2p-core/host"
"github.com/libp2p/go-libp2p-core/network"
"github.com/libp2p/go-libp2p-core/peer"
"github.com/libp2p/go-libp2p-core/peerstore"
"github.com/libp2p/go-libp2p-core/record"
"github.com/libp2p/go-eventbus"
"github.com/libp2p/go-msgio/protoio"
pb "github.com/libp2p/go-libp2p/p2p/protocol/identify/pb"
ma "github.com/multiformats/go-multiaddr"
manet "github.com/multiformats/go-multiaddr/net"
msmux "github.com/multiformats/go-multistream"
"github.com/gogo/protobuf/proto"
logging "github.com/ipfs/go-log"
)
var log = logging.Logger("net/identify")
// ID is the protocol.ID of version 1.0.0 of the identify
// service.
const ID = "/ipfs/id/1.0.0"
// LibP2PVersion holds the current protocol version for a client running this code
// TODO(jbenet): fix the versioning mess.
// XXX: Don't change this till 2020. You'll break all go-ipfs versions prior to
// 0.4.17 which asserted an exact version match.
const LibP2PVersion = "ipfs/0.1.0"
// ClientVersion is the default user agent.
//
// Deprecated: Set this with the UserAgent option.
var ClientVersion = "github.com/libp2p/go-libp2p"
var (
legacyIDSize = 2 * 1024 // 2k Bytes
signedIDSize = 8 * 1024 // 8K
maxMessages = 10
)
func init() {
bi, ok := debug.ReadBuildInfo()
if !ok {
return
}
version := bi.Main.Version
if version == "(devel)" {
ClientVersion = bi.Main.Path
} else {
ClientVersion = fmt.Sprintf("%s@%s", bi.Main.Path, bi.Main.Version)
}
}
type addPeerHandlerReq struct {
rp peer.ID
resp chan *peerHandler
}
type rmPeerHandlerReq struct {
p peer.ID
}
// IDService is a structure that implements ProtocolIdentify.
// It is a trivial service that gives the other peer some
// useful information about the local peer. A sort of hello.
//
// The IDService sends:
// * Our IPFS Protocol Version
// * Our IPFS Agent Version
// * Our public Listen Addresses
type IDService struct {
Host host.Host
UserAgent string
ctx context.Context
ctxCancel context.CancelFunc
// ensure we shutdown ONLY once
closeSync sync.Once
// track resources that need to be shut down before we shut down
refCount sync.WaitGroup
disableSignedPeerRecord bool
// Identified connections (finished and in progress).
connsMu sync.RWMutex
conns map[network.Conn]chan struct{}
addrMu sync.Mutex
// our own observed addresses.
observedAddrs *ObservedAddrManager
emitters struct {
evtPeerProtocolsUpdated event.Emitter
evtPeerIdentificationCompleted event.Emitter
evtPeerIdentificationFailed event.Emitter
}
addPeerHandlerCh chan addPeerHandlerReq
rmPeerHandlerCh chan rmPeerHandlerReq
}
// NewIDService constructs a new *IDService and activates it by
// attaching its stream handler to the given host.Host.
func NewIDService(h host.Host, opts ...Option) *IDService {
var cfg config
for _, opt := range opts {
opt(&cfg)
}
userAgent := ClientVersion
if cfg.userAgent != "" {
userAgent = cfg.userAgent
}
hostCtx, cancel := context.WithCancel(context.Background())
s := &IDService{
Host: h,
UserAgent: userAgent,
ctx: hostCtx,
ctxCancel: cancel,
conns: make(map[network.Conn]chan struct{}),
observedAddrs: NewObservedAddrManager(hostCtx, h),
disableSignedPeerRecord: cfg.disableSignedPeerRecord,
addPeerHandlerCh: make(chan addPeerHandlerReq),
rmPeerHandlerCh: make(chan rmPeerHandlerReq),
}
// handle local protocol handler updates, and push deltas to peers.
var err error
s.refCount.Add(1)
go s.loop()
s.emitters.evtPeerProtocolsUpdated, err = h.EventBus().Emitter(&event.EvtPeerProtocolsUpdated{})
if err != nil {
log.Warnf("identify service not emitting peer protocol updates; err: %s", err)
}
s.emitters.evtPeerIdentificationCompleted, err = h.EventBus().Emitter(&event.EvtPeerIdentificationCompleted{})
if err != nil {
log.Warnf("identify service not emitting identification completed events; err: %s", err)
}
s.emitters.evtPeerIdentificationFailed, err = h.EventBus().Emitter(&event.EvtPeerIdentificationFailed{})
if err != nil {
log.Warnf("identify service not emitting identification failed events; err: %s", err)
}
// register protocols that do not depend on peer records.
h.SetStreamHandler(IDDelta, s.deltaHandler)
h.SetStreamHandler(ID, s.sendIdentifyResp)
h.SetStreamHandler(IDPush, s.pushHandler)
h.Network().Notify((*netNotifiee)(s))
return s
}
func (ids *IDService) loop() {
defer ids.refCount.Done()
phs := make(map[peer.ID]*peerHandler)
sub, err := ids.Host.EventBus().Subscribe([]interface{}{&event.EvtLocalProtocolsUpdated{},
&event.EvtLocalAddressesUpdated{}}, eventbus.BufSize(256))
if err != nil {
log.Errorf("failed to subscribe to events on the bus, err=%s", err)
return
}
phClosedCh := make(chan peer.ID)
defer func() {
sub.Close()
// The context will cancel the workers. Now, wait for them to
// exit.
for range phs {
<-phClosedCh
}
}()
// Use a fresh context for the handlers. Otherwise, they'll get canceled
// before we're ready to shutdown and they'll have "stopped" without us
// _calling_ stop.
handlerCtx, cancel := context.WithCancel(context.Background())
defer cancel()
for {
select {
case addReq := <-ids.addPeerHandlerCh:
rp := addReq.rp
ph, ok := phs[rp]
if !ok && ids.Host.Network().Connectedness(rp) == network.Connected {
ph = newPeerHandler(rp, ids)
ph.start(handlerCtx, func() { phClosedCh <- rp })
phs[rp] = ph
}
addReq.resp <- ph
case rmReq := <-ids.rmPeerHandlerCh:
rp := rmReq.p
if ids.Host.Network().Connectedness(rp) != network.Connected {
// before we remove the peerhandler, we should ensure that it will not send any
// more messages. Otherwise, we might create a new handler and the Identify response
// synchronized with the new handler might be overwritten by a message sent by this "old" handler.
ph, ok := phs[rp]
if !ok {
// move on, move on, there's nothing to see here.
continue
}
// This is idempotent if already stopped.
ph.stop()
}
case rp := <-phClosedCh:
ph := phs[rp]
// If we are connected to the peer, it means that we got a connection from the peer
// before we could finish removing it's handler on the previous disconnection.
// If we delete the handler, we wont be able to push updates to it
// till we see a new connection. So, we should restart the handler.
// The fact that we got the handler on this channel means that it's context and handler
// have completed because we write the handler to this chanel only after it closed.
if ids.Host.Network().Connectedness(rp) == network.Connected {
ph.start(handlerCtx, func() { phClosedCh <- rp })
} else {
delete(phs, rp)
}
case e, more := <-sub.Out():
if !more {
return
}
switch e.(type) {
case event.EvtLocalAddressesUpdated:
for pid := range phs {
select {
case phs[pid].pushCh <- struct{}{}:
default:
log.Debugf("dropping addr updated message for %s as buffer full", pid.Pretty())
}
}
case event.EvtLocalProtocolsUpdated:
for pid := range phs {
select {
case phs[pid].deltaCh <- struct{}{}:
default:
log.Debugf("dropping protocol updated message for %s as buffer full", pid.Pretty())
}
}
}
case <-ids.ctx.Done():
return
}
}
}
// Close shuts down the IDService
func (ids *IDService) Close() error {
ids.closeSync.Do(func() {
ids.ctxCancel()
ids.refCount.Wait()
})
return nil
}
// OwnObservedAddrs returns the addresses peers have reported we've dialed from
func (ids *IDService) OwnObservedAddrs() []ma.Multiaddr {
return ids.observedAddrs.Addrs()
}
func (ids *IDService) ObservedAddrsFor(local ma.Multiaddr) []ma.Multiaddr {
return ids.observedAddrs.AddrsFor(local)
}
// IdentifyConn synchronously triggers an identify request on the connection and
// waits for it to complete. If the connection is being identified by another
// caller, this call will wait. If the connection has already been identified,
// it will return immediately.
func (ids *IDService) IdentifyConn(c network.Conn) {
<-ids.IdentifyWait(c)
}
// IdentifyWait triggers an identify (if the connection has not already been
// identified) and returns a channel that is closed when the identify protocol
// completes.
func (ids *IDService) IdentifyWait(c network.Conn) <-chan struct{} {
ids.connsMu.RLock()
wait, found := ids.conns[c]
ids.connsMu.RUnlock()
if found {
return wait
}
ids.connsMu.Lock()
defer ids.connsMu.Unlock()
wait, found = ids.conns[c]
if !found {
wait = make(chan struct{})
ids.conns[c] = wait
// Spawn an identify. The connection may actually be closed
// already, but that doesn't really matter. We'll fail to open a
// stream then forget the connection.
go ids.identifyConn(c, wait)
}
return wait
}
func (ids *IDService) removeConn(c network.Conn) {
ids.connsMu.Lock()
delete(ids.conns, c)
ids.connsMu.Unlock()
}
func (ids *IDService) identifyConn(c network.Conn, signal chan struct{}) {
var (
s network.Stream
err error
)
defer func() {
close(signal)
// emit the appropriate event.
if p := c.RemotePeer(); err == nil {
ids.emitters.evtPeerIdentificationCompleted.Emit(event.EvtPeerIdentificationCompleted{Peer: p})
} else {
ids.emitters.evtPeerIdentificationFailed.Emit(event.EvtPeerIdentificationFailed{Peer: p, Reason: err})
}
}()
s, err = c.NewStream(context.TODO())
if err != nil {
log.Debugw("error opening identify stream", "error", err)
// the connection is probably already closed if we hit this.
// TODO: Remove this?
c.Close()
// We usually do this on disconnect, but we may have already
// processed the disconnect event.
ids.removeConn(c)
return
}
s.SetProtocol(ID)
// ok give the response to our handler.
if err = msmux.SelectProtoOrFail(ID, s); err != nil {
log.Event(context.TODO(), "IdentifyOpenFailed", c.RemotePeer(), logging.Metadata{"error": err})
s.Reset()
return
}
ids.handleIdentifyResponse(s)
}
func (ids *IDService) sendIdentifyResp(s network.Stream) {
var ph *peerHandler
defer func() {
_ = s.Close()
if ph != nil {
ph.snapshotMu.RUnlock()
}
}()
c := s.Conn()
phCh := make(chan *peerHandler, 1)
select {
case ids.addPeerHandlerCh <- addPeerHandlerReq{c.RemotePeer(), phCh}:
case <-ids.ctx.Done():
return
}
select {
case ph = <-phCh:
case <-ids.ctx.Done():
return
}
if ph == nil {
// Peer disconnected, abort.
s.Reset()
return
}
ph.snapshotMu.RLock()
ids.writeChunkedIdentifyMsg(c, ph.snapshot, s)
log.Debugf("%s sent message to %s %s", ID, c.RemotePeer(), c.RemoteMultiaddr())
}
func (ids *IDService) handleIdentifyResponse(s network.Stream) {
c := s.Conn()
r := protoio.NewDelimitedReader(s, signedIDSize)
mes := &pb.Identify{}
if err := readAllIDMessages(r, mes); err != nil {
log.Warning("error reading identify message: ", err)
s.Reset()
return
}
defer s.Close()
log.Debugf("%s received message from %s %s", s.Protocol(), c.RemotePeer(), c.RemoteMultiaddr())
ids.consumeMessage(mes, c)
}
func readAllIDMessages(r protoio.Reader, finalMsg proto.Message) error {
mes := &pb.Identify{}
for i := 0; i < maxMessages; i++ {
switch err := r.ReadMsg(mes); err {
case io.EOF:
return nil
case nil:
proto.Merge(finalMsg, mes)
default:
return err
}
}
return fmt.Errorf("too many parts")
}
func (ids *IDService) getSnapshot() *identifySnapshot {
snapshot := new(identifySnapshot)
if !ids.disableSignedPeerRecord {
if cab, ok := peerstore.GetCertifiedAddrBook(ids.Host.Peerstore()); ok {
snapshot.record = cab.GetPeerRecord(ids.Host.ID())
}
}
snapshot.addrs = ids.Host.Addrs()
snapshot.protocols = ids.Host.Mux().Protocols()
return snapshot
}
func (ids *IDService) writeChunkedIdentifyMsg(c network.Conn, snapshot *identifySnapshot, s network.Stream) error {
mes := ids.createBaseIdentifyResponse(c, snapshot)
sr := ids.getSignedRecord(snapshot)
mes.SignedPeerRecord = sr
writer := protoio.NewDelimitedWriter(s)
if sr == nil || proto.Size(mes) <= legacyIDSize {
return writer.WriteMsg(mes)
}
mes.SignedPeerRecord = nil
if err := writer.WriteMsg(mes); err != nil {
return err
}
// then write just the signed record
m := &pb.Identify{SignedPeerRecord: sr}
err := writer.WriteMsg(m)
return err
}
func (ids *IDService) createBaseIdentifyResponse(
conn network.Conn,
snapshot *identifySnapshot,
) *pb.Identify {
mes := &pb.Identify{}
remoteAddr := conn.RemoteMultiaddr()
localAddr := conn.LocalMultiaddr()
// set protocols this node is currently handling
mes.Protocols = snapshot.protocols
// observed address so other side is informed of their
// "public" address, at least in relation to us.
mes.ObservedAddr = remoteAddr.Bytes()
// populate unsigned addresses.
// peers that do not yet support signed addresses will need this.
// Note: LocalMultiaddr is sometimes 0.0.0.0
viaLoopback := manet.IsIPLoopback(localAddr) || manet.IsIPLoopback(remoteAddr)
mes.ListenAddrs = make([][]byte, 0, len(snapshot.addrs))
for _, addr := range snapshot.addrs {
if !viaLoopback && manet.IsIPLoopback(addr) {
continue
}
mes.ListenAddrs = append(mes.ListenAddrs, addr.Bytes())
}
// set our public key
ownKey := ids.Host.Peerstore().PubKey(ids.Host.ID())
// check if we even have a public key.
if ownKey == nil {
// public key is nil. We are either using insecure transport or something erratic happened.
// check if we're even operating in "secure mode"
if ids.Host.Peerstore().PrivKey(ids.Host.ID()) != nil {
// private key is present. But NO public key. Something bad happened.
log.Errorf("did not have own public key in Peerstore")
}
// if neither of the key is present it is safe to assume that we are using an insecure transport.
} else {
// public key is present. Safe to proceed.
if kb, err := ownKey.Bytes(); err != nil {
log.Errorf("failed to convert key to bytes")
} else {
mes.PublicKey = kb
}
}
// set protocol versions
pv := LibP2PVersion
av := ids.UserAgent
mes.ProtocolVersion = &pv
mes.AgentVersion = &av
return mes
}
func (ids *IDService) getSignedRecord(snapshot *identifySnapshot) []byte {
if ids.disableSignedPeerRecord || snapshot.record == nil {
return nil
}
recBytes, err := snapshot.record.Marshal()
if err != nil {
log.Errorw("failed to marshal signed record", "err", err)
return nil
}
return recBytes
}
func (ids *IDService) consumeMessage(mes *pb.Identify, c network.Conn) {
p := c.RemotePeer()
// mes.Protocols
ids.Host.Peerstore().SetProtocols(p, mes.Protocols...)
// mes.ObservedAddr
ids.consumeObservedAddress(mes.GetObservedAddr(), c)
// mes.ListenAddrs
laddrs := mes.GetListenAddrs()
lmaddrs := make([]ma.Multiaddr, 0, len(laddrs))
for _, addr := range laddrs {
maddr, err := ma.NewMultiaddrBytes(addr)
if err != nil {
log.Debugf("%s failed to parse multiaddr from %s %s", ID,
p, c.RemoteMultiaddr())
continue
}
lmaddrs = append(lmaddrs, maddr)
}
// NOTE: Do not add `c.RemoteMultiaddr()` to the peerstore if the remote
// peer doesn't tell us to do so. Otherwise, we'll advertise it.
//
// This can cause an "addr-splosion" issue where the network will slowly
// gossip and collect observed but unadvertised addresses. Given a NAT
// that picks random source ports, this can cause DHT nodes to collect
// many undialable addresses for other peers.
// add certified addresses for the peer, if they sent us a signed peer record
// otherwise use the unsigned addresses.
var signedPeerRecord *record.Envelope
signedPeerRecord, err := signedPeerRecordFromMessage(mes)
if err != nil {
log.Errorf("error getting peer record from Identify message: %v", err)
}
// Extend the TTLs on the known (probably) good addresses.
// Taking the lock ensures that we don't concurrently process a disconnect.
ids.addrMu.Lock()
ttl := peerstore.RecentlyConnectedAddrTTL
if ids.Host.Network().Connectedness(p) == network.Connected {
ttl = peerstore.ConnectedAddrTTL
}
// Downgrade connected and recently connected addrs to a temporary TTL.
for _, ttl := range []time.Duration{
peerstore.RecentlyConnectedAddrTTL,
peerstore.ConnectedAddrTTL,
} {
ids.Host.Peerstore().UpdateAddrs(p, ttl, peerstore.TempAddrTTL)
}
// add signed addrs if we have them and the peerstore supports them
cab, ok := peerstore.GetCertifiedAddrBook(ids.Host.Peerstore())
if ok && signedPeerRecord != nil {
_, addErr := cab.ConsumePeerRecord(signedPeerRecord, ttl)
if addErr != nil {
log.Debugf("error adding signed addrs to peerstore: %v", addErr)
}
} else {
ids.Host.Peerstore().AddAddrs(p, lmaddrs, ttl)
}
// Finally, expire all temporary addrs.
ids.Host.Peerstore().UpdateAddrs(p, peerstore.TempAddrTTL, 0)
ids.addrMu.Unlock()
log.Debugf("%s received listen addrs for %s: %s", c.LocalPeer(), c.RemotePeer(), lmaddrs)
// get protocol versions
pv := mes.GetProtocolVersion()
av := mes.GetAgentVersion()
ids.Host.Peerstore().Put(p, "ProtocolVersion", pv)
ids.Host.Peerstore().Put(p, "AgentVersion", av)
// get the key from the other side. we may not have it (no-auth transport)
ids.consumeReceivedPubKey(c, mes.PublicKey)
}
func (ids *IDService) consumeReceivedPubKey(c network.Conn, kb []byte) {
lp := c.LocalPeer()
rp := c.RemotePeer()
if kb == nil {
log.Debugf("%s did not receive public key for remote peer: %s", lp, rp)
return
}
newKey, err := ic.UnmarshalPublicKey(kb)
if err != nil {
log.Warningf("%s cannot unmarshal key from remote peer: %s, %s", lp, rp, err)
return
}
// verify key matches peer.ID
np, err := peer.IDFromPublicKey(newKey)
if err != nil {
log.Debugf("%s cannot get peer.ID from key of remote peer: %s, %s", lp, rp, err)
return
}
if np != rp {
// if the newKey's peer.ID does not match known peer.ID...
if rp == "" && np != "" {
// if local peerid is empty, then use the new, sent key.
err := ids.Host.Peerstore().AddPubKey(rp, newKey)
if err != nil {
log.Debugf("%s could not add key for %s to peerstore: %s", lp, rp, err)
}
} else {
// we have a local peer.ID and it does not match the sent key... error.
log.Errorf("%s received key for remote peer %s mismatch: %s", lp, rp, np)
}
return
}
currKey := ids.Host.Peerstore().PubKey(rp)
if currKey == nil {
// no key? no auth transport. set this one.
err := ids.Host.Peerstore().AddPubKey(rp, newKey)
if err != nil {
log.Debugf("%s could not add key for %s to peerstore: %s", lp, rp, err)
}
return
}
// ok, we have a local key, we should verify they match.
if currKey.Equals(newKey) {
return // ok great. we're done.
}
// weird, got a different key... but the different key MATCHES the peer.ID.
// this odd. let's log error and investigate. this should basically never happen
// and it means we have something funky going on and possibly a bug.
log.Errorf("%s identify got a different key for: %s", lp, rp)
// okay... does ours NOT match the remote peer.ID?
cp, err := peer.IDFromPublicKey(currKey)
if err != nil {
log.Errorf("%s cannot get peer.ID from local key of remote peer: %s, %s", lp, rp, err)
return
}
if cp != rp {
log.Errorf("%s local key for remote peer %s yields different peer.ID: %s", lp, rp, cp)
return
}
// okay... curr key DOES NOT match new key. both match peer.ID. wat?
log.Errorf("%s local key and received key for %s do not match, but match peer.ID", lp, rp)
}
// HasConsistentTransport returns true if the address 'a' shares a
// protocol set with any address in the green set. This is used
// to check if a given address might be one of the addresses a peer is
// listening on.
func HasConsistentTransport(a ma.Multiaddr, green []ma.Multiaddr) bool {
protosMatch := func(a, b []ma.Protocol) bool {
if len(a) != len(b) {
return false
}
for i, p := range a {
if b[i].Code != p.Code {
return false
}
}
return true
}
protos := a.Protocols()
for _, ga := range green {
if protosMatch(protos, ga.Protocols()) {
return true
}
}
return false
}
func (ids *IDService) consumeObservedAddress(observed []byte, c network.Conn) {
if observed == nil {
return
}
maddr, err := ma.NewMultiaddrBytes(observed)
if err != nil {
log.Debugf("error parsing received observed addr for %s: %s", c, err)
return
}
ids.observedAddrs.Record(c, maddr)
}
func addrInAddrs(a ma.Multiaddr, as []ma.Multiaddr) bool {
for _, b := range as {
if a.Equal(b) {
return true
}
}
return false
}
func signedPeerRecordFromMessage(msg *pb.Identify) (*record.Envelope, error) {
if msg.SignedPeerRecord == nil || len(msg.SignedPeerRecord) == 0 {
return nil, nil
}
env, _, err := record.ConsumeEnvelope(msg.SignedPeerRecord, peer.PeerRecordEnvelopeDomain)
return env, err
}
// netNotifiee defines methods to be used with the IpfsDHT
type netNotifiee IDService
func (nn *netNotifiee) IDService() *IDService {
return (*IDService)(nn)
}
func (nn *netNotifiee) Connected(n network.Network, v network.Conn) {
nn.IDService().IdentifyWait(v)
}
func (nn *netNotifiee) Disconnected(n network.Network, v network.Conn) {
ids := nn.IDService()
// Stop tracking the connection.
ids.removeConn(v)
// undo the setting of addresses to peer.ConnectedAddrTTL we did
ids.addrMu.Lock()
defer ids.addrMu.Unlock()
if ids.Host.Network().Connectedness(v.RemotePeer()) != network.Connected {
// consider removing the peer handler for this
select {
case ids.rmPeerHandlerCh <- rmPeerHandlerReq{v.RemotePeer()}:
case <-ids.ctx.Done():
return
}
// Last disconnect.
ps := ids.Host.Peerstore()
ps.UpdateAddrs(v.RemotePeer(), peerstore.ConnectedAddrTTL, peerstore.RecentlyConnectedAddrTTL)
}
}
func (nn *netNotifiee) OpenedStream(n network.Network, v network.Stream) {}
func (nn *netNotifiee) ClosedStream(n network.Network, v network.Stream) {}
func (nn *netNotifiee) Listen(n network.Network, a ma.Multiaddr) {}
func (nn *netNotifiee) ListenClose(n network.Network, a ma.Multiaddr) {}