p2p: report-peer-id option for listen

License: MIT
Signed-off-by: Łukasz Magiera <magik6k@gmail.com>

core/commands/p2p.go

@@ -53,6 +53,7 @@ type P2PStreamsOutput struct {
 
 const (
 	allowCustomProtocolOptionName = "allow-custom-protocol"
+	reportPeerIDOptionName        = "report-peer-id"
 )
 
 var resolveTimeout = 10 * time.Second
@@ -183,6 +184,7 @@ Example:
 	},
 	Options: []cmdkit.Option{
 		cmdkit.BoolOption(allowCustomProtocolOptionName, "Don't require /x/ prefix"),
+		cmdkit.BoolOption(reportPeerIDOptionName, "r", "Send remote base58 peerid to target when a new connection is established"),
 	},
 	Run: func(req *cmds.Request, res cmds.ResponseEmitter, env cmds.Environment) error {
 		n, err := p2pGetNode(env)
@@ -206,15 +208,14 @@ Example:
 		}
 
 		allowCustom, _ := req.Options[allowCustomProtocolOptionName].(bool)
-		if err != nil {
-			return err
-		}
+		reportPeerID, _ := req.Options[reportPeerIDOptionName].(bool)
 
 		if !allowCustom && !strings.HasPrefix(string(proto), P2PProtoPrefix) {
 			return errors.New("protocol name must be within '" + P2PProtoPrefix + "' namespace")
 		}
 
-		return forwardRemote(n.Context(), n.P2P, proto, target)
+		_, err = n.P2P.ForwardRemote(n.Context(), proto, target, reportPeerID)
+		return err
 	},
 }
 
@@ -252,13 +253,6 @@ func checkPort(target ma.Multiaddr) error {
 	return nil
 }
 
-// forwardRemote forwards libp2p service connections to a manet address
-func forwardRemote(ctx context.Context, p *p2p.P2P, proto protocol.ID, target ma.Multiaddr) error {
-	// TODO: return some info
-	_, err := p.ForwardRemote(ctx, proto, target)
-	return err
-}
-
 // forwardLocal forwards local connections to a libp2p service
 func forwardLocal(ctx context.Context, p *p2p.P2P, ps pstore.Peerstore, proto protocol.ID, bindAddr ma.Multiaddr, addrs []ipfsaddr.IPFSAddr) error {
 	for _, addr := range addrs {

p2p/remote.go

@@ -2,6 +2,7 @@ package p2p
 
 import (
 	"context"
+	"fmt"
 
 	manet "gx/ipfs/QmQVUtnrNGtCRkCMpXgpApfzQjc8FDaDVxHqWH8cnZQeh5/go-multiaddr-net"
 	ma "gx/ipfs/QmRKLtwMw131aK7ugC3G7ybpumMz78YrJe5dzneyindvG1/go-multiaddr"
@@ -20,15 +21,21 @@ type remoteListener struct {
 
 	// Address to proxy the incoming connections to
 	addr ma.Multiaddr
+
+	// reportRemote if set to true makes the handler send '<base58 remote peerid>\n'
+	// to target before any data is forwarded
+	reportRemote bool
 }
 
 // ForwardRemote creates new p2p listener
-func (p2p *P2P) ForwardRemote(ctx context.Context, proto protocol.ID, addr ma.Multiaddr) (Listener, error) {
+func (p2p *P2P) ForwardRemote(ctx context.Context, proto protocol.ID, addr ma.Multiaddr, reportRemote bool) (Listener, error) {
 	listener := &remoteListener{
 		p2p: p2p,
 
 		proto: proto,
 		addr:  addr,
+
+		reportRemote: reportRemote,
 	}
 
 	if err := p2p.ListenersP2P.Register(listener); err != nil {
@@ -47,6 +54,13 @@ func (l *remoteListener) handleStream(remote net.Stream) {
 
 	peer := remote.Conn().RemotePeer()
 
+	if l.reportRemote {
+		if _, err := fmt.Fprintf(local, "%s\n", peer.Pretty()); err != nil {
+			remote.Reset()
+			return
+		}
+	}
+
 	peerMa, err := ma.NewMultiaddr(maPrefix + peer.Pretty())
 	if err != nil {
 		remote.Reset()