该仓库没有参考价值，本人不是从事该方面工作，研究纯属兴趣。如有需要请直接看go-libp2p的example和对应的源码。
解决在NAT后面的两个节点之间进行通信
$ git clone https://github.com/zfunnily/hole-punching-go-libp2p.git hole-punching编译 & 启动
$ cd hole-punching && go mod tidy
$ ./build.sh启动中继服务
./relay -sp 3001
2021/11/08 15:10:01 Run './chat -relay /ip4/172.16.3.205/tcp/3001/p2p/QmVJoYJC447ZVqQxWfWUecFAXPFd6QbT9mQvHuew3jaCBd' on another console.
2021/11/08 15:10:01 You can replace 192.168.0.100 with public IP as well.
2021/11/08 15:10:01 Waiting for incoming connection在窗口A启动chat 连上中继
./chat -relay /ip4/172.16.3.205/tcp/3001/p2p/QmVJoYJC447ZVqQxWfWUecFAXPFd6QbT9mQvHuew3jaCBd
2021/11/08 15:10:09 start ConnectNodeByRelay.... QmWtaMSNakQ8x5LUf4TpMb9JQy3PPSTPS4yNjRFyxAmaom /ip4/172.16.3.205/tcp/56309
2021/11/08 15:10:09 receive onFirstP2PMsg: Hello Im QmT2qBsSWkTHPHkgfd6aUZQiF7j2ArmWF9NwQ8R62Wixrw在窗口B启动chat 连上中继
./chat -relay /ip4/172.16.3.205/tcp/3001/p2p/QmVJoYJC447ZVqQxWfWUecFAXPFd6QbT9mQvHuew3jaCBd
2021/11/08 15:10:09 start ConnectNodeByRelay.... QmT2qBsSWkTHPHkgfd6aUZQiF7j2ArmWF9NwQ8R62Wixrw /ip4/172.16.3.205/tcp/56306
2021/11/08 15:10:09 receive onFirstP2PMsg: Hello Im QmWtaMSNakQ8x5LUf4TpMb9JQy3PPSTPS4yNjRFyxAmaom
2021/11/08 15:10:14 Cmdp2p start ....
2021/11/08 15:10:14 opening p2p chat stream
2021/11/08 15:10:14 [INFO] p2p chat connected!- A和B连上了中继后，中继服务会返回对方的地址 s.Conn.RemoteMultiaddr()
- A和B接收到了地址后，发送了第一条消息
FirstP2PMsg后，则过了5秒后直连对方节点n.HoleService.DirectConnect(peerInfo.ID)，代码可见,(自动p2p打洞). - A和B可以进行p2p沟通。可以试着把relay-server关闭，然后继续发送消息。可见消息能发送成功。
这里p2p的打洞流程参考 coordination.go:
func (hs *Service) handleNewStream(s network.Stream) {
// Check directionality of the underlying connection.
// Peer A receives an inbound connection from peer B.
// Peer A opens a new hole punch stream to peer B.
// Peer B receives this stream, calling this function.
// Peer B sees the underlying connection as an outbound connection.
}- 22/04/29 增加一个ubuntu下可执行的relay-server
- 22/04/29 chat.go注释直连代码. 只能通过中继模式通信。
- go-libp2p的代码打洞的代码都已经写好了。看测试用例，理解了之后就能写出来了。
- 后续有时间再研究。