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Module: the modular p2 p networking stack
- 1. Module: The modular P2P networkingstack ResNetLab on Tour
- 2. ➔ Why libp2p?Decentralized Process Addressing ➔ libp2p: From modules to innovation ➔ libp2p modules ◆ Transports ◆ Multiplexers ◆ Secure Channels ◆ Peer Discovery ◆ Content and Peer Routing ◆ NAT Traversal ◆ PubSub ➔ Pluggable modules Agenda
- 3. Composable building blocksto assemble future-proof p2p networking layers Runs on many runtimes: browser, mobile, embedded. Substrate for innovation on new protocols (composable modules) Implemented in 7+ languages A modular peer-to-peer networking stack
- 4. Decentralized Process Addressing Why? ●Ability to locate, connect, authenticate, negotiate and interact efficiently with any process in the world ○ Independent of the runtime ○ In a seamless manner (NAT-traversal, heterogeneous networks, relays). ○ Fully operational even in a case of mobility, relocation, roam, etc. ○ Every peer is uniquely identified. ● Network- and topology-independent alternative to endpoint addressing (e.g. IP networks)
- 5. Where does libp2plive? Where? Data-link Layer Physical Layer Transport
- 6. Networking Innovation ● libp2p’s modularprotocol stack fosters innovation through the design of new protocols and layers. ● It provides all the interfaces required for fast implementation. ● The substrate for new applications and protocols. ● Recent example: Compression in libp2p From modules to innovation (and back) libp2p protocol layers Security (Noise / TLS) Transport (TCP / UDP / QUIC) Muxer (yamux / multiplex) Application protocols https://github.com/adlrocha/go-libp2p-c ompression-examples Security (Noise / TLS) Transport (TCP / UDP / QUIC) Muxer (yamux / multiplex) Application protocols Compression (gzip)
- 7. Decentralized Process Addressing PeerIdentity ● Uniquely identifies peers ● IDs derived from their public key ○ Four key types: RSA, Ed25519, SEC256k1, ECDSA ○ Multihash representation ■ Identity multihash (i.e. no hash) if public key < 48 bytes ■ SHA-256 of multihash if > 48 bytes Multiaddress /ip4/1.2.3.4/tcp/5001/p2p/<peer_id> ● Network processes are named as filepaths. ● Specify available processes in a peer in a single address ● Used for dialing peer Hash code Hash bytes QmSoLPppuBtQSGwKDZT2M73ULpjvfd3aZ6ha4oFGL1KrGM
- 8. Transports Multiplexers Secure Channels Peer Discovery PeerRouting Content Routing NAT Traversal Pubsub
- 9. Transports Multiplexers Secure Channels Peer Discovery PeerRouting Content Routing NAT Traversal Pubsub
- 10. Transports ● Transports arecore abstractions of libp2p ○ Connection factories for communication between peers (i.e. establish new connections over specific protocol) ○ Dialing and listening ○ They produce raw connections, socket, sessions - the “L4” of libp2p ● Current transports: ○ TCP, QUIC, WebSockets, WebRTC
- 11. ● Connection bootstrappingtakes a raw connection, created by a transport, and “upgrades it” to use a secure channel and multiplexer. ○ The secure channel and multiplexer are negotiated dynamically to create a capable connection between two peers. ● Some transports don’t need upgrading. ○ QUIC handles multiplexing and encryption itself. ● All of this negotiation is done to bootstrap a connection using a protocol called multistream-select. Connection Bootstrapping
- 12. Connection Bootstrapping If the twopeers do not support the same protocols, the connection is terminated.
- 13. Transports Multiplexers Secure Channels Peer Discovery PeerRouting Content Routing NAT Traversal Pubsub
- 14. Multiplexing ● Establishing aP2P connection may not be cheap or easy (e.g. hole punching, negotiation, handshake, etc.) ● Re-use established connections for several protocols. ○ Applications can leverage already established connections. ● Streams are uniquely identified based on its multiplexer specification. ● Several implementations of multiplexers available: ○ Language specific libraries for stream multiplex (Yamux, Mplex) ○ Transport protocol native multiplexing capabilities (QUIC)
- 15. Protocol Negotiation ● Multistream-selectis the protocol negotiation scheme. Blind scheme used for connection upgrade. ● We can also identify the protocols other peers are running with: ○ Identify protocol which is run after connection upgrade. Returns list of supported protocols ○ Multistream list (ls) protocol >>> /multistream/1.0.0 (1) <<< /multistream/1.0.0 (2) >>> /foo/A (3) <<< na (4) >>> /foo/B (5) <<< /foo/B (6) >>> /ls ● Protocol IDs ○ Analogous to REST endpoints. Serve for routing and handling ○ As simple as mounting handlers for additional protocols • /floodsub/1.0.0 •/ipfs/bitswap/1.0.0 •/eth2/beacon_chain/req/..
- 16. Transports Multiplexers Secure Channels Peer Discovery PeerRouting Content Routing NAT Traversal Pubsub
- 17. Secure Channels ● Peerauthentication and transport encryption. ● Transmission integrity. Non repudiation. Message authentication ○ Does not preclude from encrypting/signing application data ● Several security protocols supported: ○ Noise: Security framework. Handshake and negotiate primitives. ○ TLS 1.3
- 18. Transports Multiplexers Secure Channels Peer Discovery PeerRouting Content Routing NAT Traversal Pubsub
- 19. Peer Discovery ● Twodiscovery interfaces: ○ Advertiser to announce services to other peers ○ Discoverer to find peers supporting certain services ● Implementations ○ MDNS ○ Kademlia DHT // Advertiser is an interface for advertising services type Advertiser interface { // Advertise advertises a service Advertise(ns string, opts ...Option) (time.Duration, error) } // Discoverer is an interface for peer discovery type Discoverer interface { // FindPeers discovers peers providing a service FindPeers(ns string, opts ...Option) (peer.AddrInfo, error) } // Discovery is an interface that combines service advertisement and peer discovery type Discovery interface { Advertiser Discoverer }
- 20. Content and PeerRouting ● Interfaces to find and advertise ○ Content-addressed chunks of data in a p2p network ○ Peer multiaddrs: libp2p-kad-dht ● This interface could implement other protocols: ○ DNS ○ BitTorrent trackers ○ Any other providing subsystems
- 21. Transports Multiplexers Secure Channels Peer Discovery PeerRouting Content Routing NAT Traversal Pubsub
- 22. NAT Traversal ● Goal:Achieve global connectivity in heterogeneous networks. ● AutoNAT ○ Request information from other peers to identify how is my network observed from the outside. ○ It determines if we’re actually reachable and reports a routability: PUBLIC, PRIVATE, UNKNOWN. ● AutoRelay ○ If a peer is not reachable from a public network: ■ It tries to discover relay peers automatically ■ It connects to them, and advertises the relays addresses as part of their own address (so others know how to reach it) ■ From there on other know how to contact me through the relay ○ Doesn’t scale well.
- 23. ● Hole punching ○Use relay servers as a conduit for hole punching signalling and sync. ○ Find close peers to our target to create temporary relayed connections. ○ Detect NAT type and use hole punching to try to upgrade to direct connection NAT Traversal
- 24. Transports Multiplexers Secure Channels Peer Discovery PeerRouting Content Routing NAT Traversal Pubsub
- 25. ● PubSub isa message-oriented communication pattern. ● M:N interaction model. Asynchronous communication. ● Peers congregate around topics. Some processes publish messages and others listen to them. Common in enterprise software with decentralized brokers. PubSub Interface
- 26. PubSub Interface ● DecentralizedP2P PubSub. ○ Brokerless, self-regulating, no global knowledge ○ Constructed as overlay networks collaborating for message deliverability ● Several available protocols ○ GossipSub ○ FloodSub ● Use cases: IPNS, content-addressing, blockchain consensus, message dissemination, etc.
- 27. Transports Multiplexers Secure Channels Peer Discovery PeerRouting Content Routing NAT Traversal Pubsub
- 28. ● libp2p modulesare “plug and play”, they can be easily be added in an application with a few lines of code. ○ Create libp2p node is simple ■ Supported transports, muxer, security channel Pluggable modules ● If my application needs additional capabilities like peer discovery, routing, etc. we don’t have to implement it from scratch: host, err := libp2p.New( context.Background(), libp2p.ListenAddrs(sourceMultiAddr), libp2p.Identity(prvKey), ) // Instantiate DHT protocol (analogous for other modules). newDHT, _ := kaddht.New(host) host, err := libp2p.New( context.Background(), libp2p.ListenAddrs(sourceMultiAddr), libp2p.Identity(prvKey), libp2p.Routing(newDHT) )
- 29. Thank you forwatching Reach out in case you have questions or comments!