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Diffstat (limited to 'src/transport/p2p.rs')
| -rw-r--r-- | src/transport/p2p.rs | 1836 |
1 files changed, 0 insertions, 1836 deletions
diff --git a/src/transport/p2p.rs b/src/transport/p2p.rs deleted file mode 100644 index 30fdb23..0000000 --- a/src/transport/p2p.rs +++ /dev/null @@ -1,1836 +0,0 @@ -//! libp2p as a transport (`--transports libp2p`, in builds with the `libp2p` feature): -//! direct connections over TCP (Noise, Yamux) and QUIC, to addresses this node knows. -//! -//! A node's transport identity is its libp2p peer ID; where it is, its listen addresses -//! (multiaddrs ending in the peer ID, `locations`). Seeds are such multiaddrs, or ones -//! without the peer ID, which a connection finds out. Messages go one per stream of the -//! `/continuum/1` protocol: their length (4 bytes, big endian), then the message as -//! `wire` encodes it. A send is done once the stream is written and closed; a connection -//! that can't be made, or a stream that can't be written, refuses it. -//! -//! Connected peers tell each other where they listen (libp2p's identify protocol), so a -//! node learns the addresses of peers that dialled it. A node publishes where it can be -//! reached (`local_addresses`): the addresses it announces (`--libp2p-announce`, e.g. a -//! public address forwarded to it), or else those it listens on, loopback left out. -//! -//! A node nobody can dial (behind NAT, or a closed port) can still be reached through a -//! relay: a node of the swarm that relays (`--libp2p-relay`), on which it reserves a slot -//! (`--libp2p-relays`); its address through the relay (`<relay>/p2p-circuit/p2p/<it>`) -//! is published with the others. Over a relayed connection, both sides then try to -//! connect directly (libp2p's DCUtR, hole punching); the relay carries the traffic until -//! that works, or for good if it doesn't, within its limits (`RELAY_CIRCUIT_DURATION`, -//! `RELAY_CIRCUIT_BYTES`; a circuit that ends is made again on the next send). -//! -//! A relay says so where it publishes its addresses: next to each, the same address -//! ending in `/p2p-circuit` (where to reserve a slot), which other nodes find in the -//! member list. A node that needs a relay and has none configured picks up to -//! `AUTO_RELAYS` of those (`relay_check`). It needs one when it has no address others -//! could dial, or when AutoNAT says it can't be dialled: AutoNAT asks connected peers -//! (nodes of the swarm) to dial it back. Once AutoNAT says it can be dialled, it lets -//! the relays it picked go. -//! -//! With `--libp2p-mdns`, a node finds libp2p peers on its LAN (multicast DNS). Their -//! LAN addresses are noted, and those that turn out to speak continuum (identify says -//! so) are seeds while the node joins (`discovered_seeds`): nodes on one LAN find each -//! other without configured seeds. -//! -//! It uses public libp2p infrastructure only with `--libp2p-public`: then it joins the -//! IPFS DHT (Kademlia, through the IPFS bootstrap nodes), where it finds addresses of -//! peers the member list doesn't have, and public peers that relay; those are picked -//! after members that relay. Public relays keep circuits short (by default 2 minutes and -//! 128 KiB): enough to punch holes through NATs, not to carry a swarm's traffic. Without -//! it, relays are those configured, or members that say they relay. - -use std::collections::HashMap; -use std::path::Path; -use std::str::FromStr; -use std::sync::{Arc, Mutex, MutexGuard}; -use std::time::Duration; - -use ::libp2p::multiaddr::Protocol; -use ::libp2p::swarm::dial_opts::{DialOpts, PeerCondition}; -use ::libp2p::swarm::{ConnectionId, SwarmEvent}; -use ::libp2p::{Multiaddr, PeerId, StreamProtocol, Swarm, identity::Keypair}; -use anyhow::{Context, Result, anyhow, bail}; -use async_trait::async_trait; -use futures::{AsyncReadExt, AsyncWriteExt, StreamExt}; -use tokio::sync::{Semaphore, mpsc, oneshot, watch}; -use tracing::{debug, info, trace, warn}; - -use crate::locks::MutexExt; -use crate::transport::stats::{ - Connections, DialFailures, HolePunches, Libp2pStats, Reachability, RelaySlots, TransportStats, -}; -use crate::transport::{ - Connection, EncodedMessage, MessageHandler, ParsedMessage, Transport, wire, -}; - -const PROTOCOL: StreamProtocol = StreamProtocol::new("/continuum/1"); -/// The largest message read: anyone who can connect can send anything, so this bounds -/// what one stream costs. Sync messages above 16 chunks travel as blobs. -const MAX_MESSAGE: usize = 128 << 20; -/// How long a connection may take to come up. -const CONNECT_TIMEOUT: Duration = Duration::from_secs(10); -/// A connection nobody uses is closed after this; neighbours keep theirs busy. -const IDLE_TIMEOUT: Duration = Duration::from_secs(300); -/// How long a stream may take to open and to carry a message, before what its size adds -/// (`stream_timeout`). -const STREAM_TIMEOUT: Duration = Duration::from_secs(10); -/// The slowest a message is expected to go, in bytes per second. -const MIN_RATE: u64 = 1 << 20; -/// Inbound streams read at once. -const READS: usize = 32; -/// Addresses kept per peer, and peers with addresses at most. -const ADDRESSES_PER_PEER: usize = 8; -const MAX_PEERS: usize = 4096; - -/// A relayed connection (circuit) through this node lasts at most this long and carries -/// at most this much: generous, since the swarm's own relays may carry sync traffic for -/// good where hole punching fails (libp2p's defaults, 2 minutes and 128 KiB, are for -/// the punching only). -const RELAY_CIRCUIT_DURATION: Duration = Duration::from_secs(3600); -const RELAY_CIRCUIT_BYTES: u64 = 1 << 30; -/// Circuits through this node at once, and per peer. -const RELAY_CIRCUITS: usize = 64; -const RELAY_CIRCUITS_PER_PEER: usize = 8; -/// A reservation on a relay that ended (the relay restarted, say) is made again after -/// this. -const RELAY_RETRY: Duration = Duration::from_secs(30); -/// Relays picked among the members, at most, and how often a node checks whether it -/// needs them. -const AUTO_RELAYS: usize = 2; -const RELAY_CHECK: Duration = Duration::from_secs(30); -/// A relay that lost the slot before granting it (it doesn't answer, or another peer -/// answers at its address: a relay restarted without its libp2p key) isn't picked again -/// for this long. -const RELAY_PAUSE: Duration = Duration::from_secs(600); -/// A peer nobody mentioned for this long (the member list, identify, mDNS, a -/// connection) is forgotten, unless connected: mostly old peer IDs of nodes restarted -/// without their libp2p key, whose new ones the member list has since. Members are -/// mentioned every few seconds (`swarm::topology`). Checked every `PRUNE_EVERY`. -const STALE_AFTER: Duration = Duration::from_secs(600); -const PRUNE_EVERY: Duration = Duration::from_secs(60); - -/// How long a message of `bytes` may take on a stream. -fn stream_timeout(bytes: usize) -> Duration { - STREAM_TIMEOUT + Duration::from_millis(bytes as u64 * 1000 / MIN_RATE) -} - -/// What a libp2p transport is made with. -pub(crate) struct Libp2pConfig { - pub(crate) key: Keypair, - /// Multiaddrs to listen on. - pub(crate) listen: Vec<Multiaddr>, - /// Multiaddrs to publish instead of the listen addresses, if any. - pub(crate) announce: Vec<Multiaddr>, - /// Relays to reserve a slot on (multiaddrs; without the relay's peer ID, a connection - /// finds it out). - pub(crate) relays: Vec<Multiaddr>, - /// Relay for other nodes. - pub(crate) relay: bool, - /// Find peers on the LAN (mDNS). - pub(crate) mdns: bool, - /// Use public infrastructure: the IPFS DHT, public relays. - pub(crate) public: bool, - /// libp2p's in-memory transport instead of TCP and QUIC: for tests. - pub(crate) memory: bool, -} - -impl Libp2pConfig { - /// The key in `path` (32 raw bytes, an Ed25519 secret key), or a new one each start - /// without a file: the peer ID only says where a node is, so a new one costs nothing - /// but the WHO that finds it again (`transport::identity`). - pub(crate) fn load_key(path: Option<&Path>) -> Result<Keypair> { - let Some(path) = path else { - return Ok(Keypair::generate_ed25519()); - }; - let mut bytes = std::fs::read(path) - .with_context(|| format!("Reading the libp2p key from {}", path.display()))?; - crate::swarm::auth::warn_if_readable_by_others(path, "libp2p key"); - if bytes.len() != 32 { - bail!( - "The libp2p key in {} has {} bytes; it has 32", - path.display(), - bytes.len() - ); - } - Keypair::ed25519_from_bytes(&mut bytes) - .map_err(|error| anyhow!("The libp2p key in {}: {error}", path.display())) - } -} - -enum Command { - /// Connect to `peer` (at `addresses`) unless connected. - Connect { - peer: PeerId, - addresses: Vec<Multiaddr>, - done: oneshot::Sender<Result<(), String>>, - }, - /// Connect to `address` to find out which peer is there. - Identify { - address: Multiaddr, - done: oneshot::Sender<Result<PeerId, String>>, - }, - /// See whether relays among the members are needed now (one was just learned of). - CheckRelays, - /// Reserve a slot on the relay at `relay` (again). `configured`: the address as - /// configured, for later attempts (without a peer ID, the relay may since have - /// another). - Reserve { - relay: Multiaddr, - configured: Multiaddr, - }, -} - -/// Where peers are, and where we listen. -#[derive(Default)] -struct Book { - addresses: HashMap<PeerId, Vec<Multiaddr>>, - listening: Vec<Multiaddr>, - /// `Libp2pConfig::announce`. - announced: Vec<Multiaddr>, - /// `Libp2pConfig::relay`: this node relays, and says so. - serving: bool, - /// Members that say they relay, and where (with the relay's peer ID). - relays: HashMap<PeerId, Multiaddr>, - /// With `Libp2pConfig::public`: other peers that relay (identify says so), and - /// where. - public_relays: HashMap<PeerId, Multiaddr>, - /// Relays picked that never granted a slot, and when (`RELAY_PAUSE`). - failed_relays: HashMap<PeerId, tokio::time::Instant>, - /// Relays that granted us a slot we hold. - slots: std::collections::HashSet<PeerId>, - /// Open connections: to whom, and whether through a relay. - connections: HashMap<ConnectionId, (PeerId, bool)>, - /// What AutoNAT says, and the address it confirmed while public. - reachability: Reachability, - public_address: Option<Multiaddr>, - /// Since start (`stats`). - counts: Counts, - /// When each peer was last mentioned (`STALE_AFTER`). - seen: HashMap<PeerId, tokio::time::Instant>, - /// Peers found on the LAN (mDNS) not known yet to speak continuum. - lan: std::collections::HashSet<PeerId>, - /// Peers that speak continuum (identify says so). - continuum: std::collections::HashSet<PeerId>, - /// Peers found on the LAN that speak continuum, with their address: seeds not - /// handed out yet (`discovered_seeds`). - discovered: Vec<Multiaddr>, -} - -/// What `Libp2pStats` counts since start. -#[derive(Default)] -struct Counts { - slots_granted: u64, - slots_lost: u64, - slots_not_granted: u64, - hole_punches: HolePunches, - dial_failures: DialFailures, -} - -/// Counts a dial that failed with `error` (not one that wasn't needed). -fn count_dial_failure(failures: &mut DialFailures, error: &::libp2p::swarm::DialError) { - use ::libp2p::swarm::DialError; - match error { - DialError::DialPeerConditionFalse(_) => {} - DialError::Transport(_) => failures.unreachable += 1, - DialError::WrongPeerId { .. } => failures.wrong_peer_id += 1, - DialError::NoAddresses => failures.no_addresses += 1, - _ => failures.other += 1, - } -} - -impl Book { - /// How we are connected to `peer`: directly if any connection is direct. - fn connection(&self, peer: &PeerId) -> Option<Connection> { - let mut found = None; - for (connected, relayed) in self.connections.values() { - if connected == peer { - if !relayed { - return Some(Connection::Direct); - } - found = Some(Connection::Relayed); - } - } - found - } - - fn stats(&self) -> Libp2pStats { - let mut connections = Connections::default(); - for (_, relayed) in self.connections.values() { - if *relayed { - connections.relayed += 1; - } else { - connections.direct += 1; - } - } - Libp2pStats { - reachability: self.reachability, - public_address: self.public_address.as_ref().map(Multiaddr::to_string), - connections, - relay_slots: RelaySlots { - held: self.slots.len(), - paused: self - .failed_relays - .values() - .filter(|at| at.elapsed() < RELAY_PAUSE) - .count(), - granted: self.counts.slots_granted, - lost: self.counts.slots_lost, - not_granted: self.counts.slots_not_granted, - }, - hole_punches: self.counts.hole_punches, - dial_failures: self.counts.dial_failures, - } - } - - /// `peer` was mentioned just now. - fn touch(&mut self, peer: PeerId) { - self.seen.insert(peer, tokio::time::Instant::now()); - } - - /// Forgets the peers not mentioned within `STALE_AFTER` before `now`, but those - /// `connected`. Returns how many. - fn prune(&mut self, now: tokio::time::Instant, connected: impl Fn(&PeerId) -> bool) -> usize { - let stale: Vec<PeerId> = self - .addresses - .keys() - .chain(self.relays.keys()) - .chain(self.public_relays.keys()) - .chain(self.continuum.iter()) - .chain(self.lan.iter()) - .filter(|peer| { - !connected(peer) - && self - .seen - .get(peer) - .is_none_or(|at| now.saturating_duration_since(*at) >= STALE_AFTER) - }) - .copied() - .collect::<std::collections::HashSet<_>>() - .into_iter() - .collect(); - for peer in &stale { - self.addresses.remove(peer); - self.relays.remove(peer); - self.public_relays.remove(peer); - self.continuum.remove(peer); - self.lan.remove(peer); - self.failed_relays.remove(peer); - self.seen.remove(peer); - } - stale.len() - } - - /// `peer`, found on the LAN, speaks continuum: a seed, at the address we know first. - fn discover(&mut self, peer: PeerId) { - let Some(address) = self.addresses.get(&peer).and_then(|known| known.first()) else { - return; - }; - if let Ok(address) = address.clone().with_p2p(peer) - && !self.discovered.contains(&address) - && self.discovered.len() < MAX_PEERS - { - self.discovered.push(address); - } - } - - /// Where others could dial us directly: the announced addresses, or else those we - /// listen on (`published`), without the peer ID. - fn direct(&self) -> Vec<Multiaddr> { - if !self.announced.is_empty() { - return self.announced.clone(); - } - let direct: Vec<Multiaddr> = self - .listening - .iter() - .filter(|address| !is_relayed(address)) - .cloned() - .collect(); - published(&direct) - } -} - -/// Whether `address` only reaches this host (or this link): no use to other hosts, and -/// dialled by one, it reaches that host itself. -fn is_local(address: &Multiaddr) -> bool { - match address.iter().next() { - Some(Protocol::Ip4(ip)) => ip.is_loopback() || ip.is_link_local() || ip.is_unspecified(), - Some(Protocol::Ip6(ip)) => { - ip.is_loopback() || ip.is_unicast_link_local() || ip.is_unspecified() - } - _ => false, - } -} - -/// The addresses of `all` worth publishing: all but local ones, unless they're all -/// local (a test on one host). -fn published(all: &[Multiaddr]) -> Vec<Multiaddr> { - let reachable: Vec<Multiaddr> = all - .iter() - .filter(|address| !is_local(address)) - .cloned() - .collect(); - if reachable.is_empty() { - all.to_vec() - } else { - reachable - } -} - -impl Book { - /// Whether all of `addresses` are known of `peer` (`remember`). - fn knows(&self, peer: PeerId, addresses: &[Multiaddr]) -> bool { - let Some(known) = self.addresses.get(&peer) else { - return false; - }; - addresses.iter().all(|address| { - let mut address = address.clone(); - if let Some(Protocol::P2p(_)) = address.iter().last() { - address.pop(); - } - known.contains(&address) - }) - } - - /// `peer` is at `address` (without its `/p2p` part): kept first. - fn remember(&mut self, peer: PeerId, mut address: Multiaddr) { - if let Some(Protocol::P2p(_)) = address.iter().last() { - address.pop(); - } - if !self.addresses.contains_key(&peer) && self.addresses.len() >= MAX_PEERS { - return; - } - self.touch(peer); - let addresses = self.addresses.entry(peer).or_default(); - addresses.retain(|known| *known != address); - addresses.insert(0, address); - addresses.truncate(ADDRESSES_PER_PEER); - } -} - -/// Whether `address` goes through a relay. -fn is_relayed(address: &Multiaddr) -> bool { - address - .iter() - .any(|protocol| matches!(protocol, Protocol::P2pCircuit)) -} - -/// The relay `address` goes through, if it goes through one: the peer before -/// `/p2p-circuit`. -fn relay_of(address: &Multiaddr) -> Option<PeerId> { - let mut relay = None; - for protocol in address.iter() { - match protocol { - Protocol::P2p(peer) => relay = Some(peer), - Protocol::P2pCircuit => return relay, - _ => {} - } - } - None -} - -/// The addresses of `known` this node can dial: not those through itself as the relay -/// (a relay reaches the nodes it relays for only while they are connected to it). -fn dialable(known: &[Multiaddr], local: PeerId) -> Vec<Multiaddr> { - known - .iter() - .filter(|address| relay_of(address) != Some(local)) - .cloned() - .collect() -} - -/// `address` with the peer ID it ends in, if it ends in one. -fn split_peer(address: &Multiaddr) -> Option<PeerId> { - match address.iter().last() { - Some(Protocol::P2p(peer)) => Some(peer), - _ => None, - } -} - -pub(crate) struct Libp2pTransport { - local_id: String, - peer_id: PeerId, - control: libp2p_stream::Control, - commands: mpsc::UnboundedSender<Command>, - book: Arc<Mutex<Book>>, - incoming: tokio::sync::Mutex<Option<libp2p_stream::IncomingStreams>>, - stopped: watch::Receiver<bool>, -} - -fn lock(book: &Mutex<Book>) -> MutexGuard<'_, Book> { - book.lock_or_recover() -} - -impl Libp2pTransport { - /// Builds the swarm, listens, and runs it in a task of its own. - pub(crate) fn start(config: Libp2pConfig) -> Result<Self> { - let peer_id = config.key.public().to_peer_id(); - let features = Features::of(&config); - let mut swarm = if config.memory { - memory_swarm(config.key, features)? - } else { - network_swarm(config.key, features)? - }; - for address in config.listen { - swarm - .listen_on(address.clone()) - .with_context(|| format!("Listening on {address}"))?; - } - for address in &config.announce { - // Identify tells peers these. - swarm.add_external_address(address.clone()); - } - let mut control = swarm.behaviour().stream.new_control(); - let incoming = control - .accept(PROTOCOL) - .map_err(|error| anyhow!("Accepting {PROTOCOL}: {error}"))?; - let configured_relays = !config.relays.is_empty(); - let book = Arc::new(Mutex::new(Book { - announced: config.announce, - serving: config.relay, - ..Book::default() - })); - let (commands, receiver) = mpsc::unbounded_channel(); - for relay in config.relays { - let _ = commands.send(Command::Reserve { - configured: relay.clone(), - relay, - }); - } - let (stopping, stopped) = watch::channel(false); - tokio::spawn(run( - swarm, - receiver, - commands.clone(), - Arc::clone(&book), - Relaying { - serving: config.relay, - configured: configured_relays, - public: config.public, - local: peer_id, - }, - stopping, - )); - info!(peer_id = %peer_id, "libp2p transport started"); - Ok(Self { - local_id: peer_id.to_string(), - peer_id, - control, - commands, - book, - incoming: tokio::sync::Mutex::new(Some(incoming)), - stopped, - }) - } - - /// Connected to `peer`, if it can be had in time. - async fn connect(&self, peer: PeerId) -> Result<()> { - let addresses = lock(&self.book) - .addresses - .get(&peer) - .map(|known| dialable(known, self.peer_id)) - .unwrap_or_default(); - let (done, connected) = oneshot::channel(); - self.commands - .send(Command::Connect { - peer, - addresses, - done, - }) - .map_err(|_| anyhow!("the libp2p swarm stopped"))?; - match tokio::time::timeout(CONNECT_TIMEOUT, connected).await { - Ok(Ok(Ok(()))) => Ok(()), - Ok(Ok(Err(error))) => bail!("couldn't connect to {peer}: {error}"), - Ok(Err(_)) => bail!("the libp2p swarm stopped"), - Err(_) => bail!("connecting to {peer} took longer than {CONNECT_TIMEOUT:?}"), - } - } -} - -/// The protocol version identify says (informational: nothing checks it). -const IDENTIFY_VERSION: &str = "/continuum/1"; - -#[derive(::libp2p::swarm::NetworkBehaviour)] -struct Behaviour { - stream: libp2p_stream::Behaviour, - identify: ::libp2p::identify::Behaviour, - relay_client: ::libp2p::relay::client::Behaviour, - /// Only with `Libp2pConfig::relay`. - relay: ::libp2p::swarm::behaviour::toggle::Toggle<::libp2p::relay::Behaviour>, - dcutr: ::libp2p::dcutr::Behaviour, - autonat: ::libp2p::autonat::Behaviour, - /// Only with `Libp2pConfig::mdns`. - mdns: ::libp2p::swarm::behaviour::toggle::Toggle<::libp2p::mdns::tokio::Behaviour>, - /// Only with `Libp2pConfig::public`: the IPFS DHT. - kad: ::libp2p::swarm::behaviour::toggle::Toggle< - ::libp2p::kad::Behaviour<::libp2p::kad::store::MemoryStore>, - >, -} - -/// What the behaviour has besides what every node has. -#[derive(Clone, Copy)] -struct Features { - relay: bool, - mdns: bool, - public: bool, -} - -impl Features { - fn of(config: &Libp2pConfig) -> Self { - Self { - relay: config.relay, - mdns: config.mdns, - public: config.public, - } - } -} - -/// The IPFS DHT's protocol, and its bootstrap nodes (all at `IPFS_BOOTSTRAP_ADDRESS`). -const IPFS_DHT: StreamProtocol = StreamProtocol::new("/ipfs/kad/1.0.0"); -const IPFS_BOOTSTRAP_ADDRESS: &str = "/dnsaddr/bootstrap.libp2p.io"; -const IPFS_BOOTSTRAP_PEERS: [&str; 4] = [ - "QmNnooDu7bfjPFoTZYxMNLWUQJyrVwtbZg5gBMjTezGAJN", - "QmQCU2EcMqAqQPR2i9bChDtGNJchTbq5TbXJJ16u19uLTa", - "QmbLHAnMoJPWSCR5Zhtx6BHJX9KiKNN6tpvbUcqanj75Nb", - "QmcZf59bWwK5XFi76CZX8cbJ4BhTzzA3gU1ZjYZcYW3dwt", -]; -/// How often a node on the DHT refreshes its routing table. -const DHT_BOOTSTRAP: Duration = Duration::from_secs(300); - -impl Behaviour { - fn new( - key: &Keypair, - relay_client: ::libp2p::relay::client::Behaviour, - features: Features, - ) -> std::io::Result<Self> { - let Features { - relay, - mdns, - public, - } = features; - let peer_id = key.public().to_peer_id(); - let kad = public.then(|| { - let mut dht = ::libp2p::kad::Behaviour::with_config( - peer_id, - ::libp2p::kad::store::MemoryStore::new(peer_id), - ::libp2p::kad::Config::new(IPFS_DHT), - ); - let bootstrap: Multiaddr = IPFS_BOOTSTRAP_ADDRESS.parse().expect("a multiaddr"); - for peer in IPFS_BOOTSTRAP_PEERS { - let peer: PeerId = peer.parse().expect("a peer ID"); - let _ = dht.add_address(&peer, bootstrap.clone()); - } - dht - }); - let identify = ::libp2p::identify::Config::new(IDENTIFY_VERSION.to_owned(), key.public()) - .with_agent_version(format!("continuum/{}", env!("CARGO_PKG_VERSION"))); - let relay = relay.then(|| { - ::libp2p::relay::Behaviour::new( - peer_id, - ::libp2p::relay::Config { - max_circuits: RELAY_CIRCUITS, - max_circuits_per_peer: RELAY_CIRCUITS_PER_PEER, - max_circuit_duration: RELAY_CIRCUIT_DURATION, - max_circuit_bytes: RELAY_CIRCUIT_BYTES, - ..Default::default() - }, - ) - }); - let mdns = match mdns { - true => Some(::libp2p::mdns::tokio::Behaviour::new( - ::libp2p::mdns::Config::default(), - peer_id, - )?), - false => None, - }; - Ok(Self { - stream: libp2p_stream::Behaviour::new(), - identify: ::libp2p::identify::Behaviour::new(identify), - relay_client, - relay: relay.into(), - dcutr: ::libp2p::dcutr::Behaviour::new(peer_id), - autonat: ::libp2p::autonat::Behaviour::new( - peer_id, - ::libp2p::autonat::Config { - // Swarms on private networks (a LAN, WireGuard) count too. - only_global_ips: false, - ..Default::default() - }, - ), - mdns: mdns.into(), - kad: kad.into(), - }) - } -} - -fn network_swarm(key: Keypair, features: Features) -> Result<Swarm<Behaviour>> { - Ok(::libp2p::SwarmBuilder::with_existing_identity(key) - .with_tokio() - .with_tcp( - ::libp2p::tcp::Config::default(), - ::libp2p::noise::Config::new, - ::libp2p::yamux::Config::default, - )? - .with_quic() - .with_dns()? - .with_relay_client( - ::libp2p::noise::Config::new, - ::libp2p::yamux::Config::default, - )? - .with_behaviour(|key, relay_client| { - Behaviour::new(key, relay_client, features) - .map_err(|error| Box::new(error) as Box<dyn std::error::Error + Send + Sync>) - })? - .with_swarm_config(|config| config.with_idle_connection_timeout(IDLE_TIMEOUT)) - .build()) -} - -fn memory_swarm(key: Keypair, features: Features) -> Result<Swarm<Behaviour>> { - use ::libp2p::Transport as _; - use ::libp2p::core::transport::{MemoryTransport, OrTransport}; - use ::libp2p::core::upgrade::Version; - - let peer_id = key.public().to_peer_id(); - let (relay_transport, relay_client) = ::libp2p::relay::client::new(peer_id); - let transport = OrTransport::new(relay_transport, MemoryTransport::default()) - .boxed() - .upgrade(Version::V1) - .authenticate(::libp2p::noise::Config::new(&key)?) - .multiplex(::libp2p::yamux::Config::default()) - .timeout(CONNECT_TIMEOUT) - .boxed(); - Ok(Swarm::new( - transport, - Behaviour::new(&key, relay_client, features)?, - peer_id, - ::libp2p::swarm::Config::with_tokio_executor().with_idle_connection_timeout(IDLE_TIMEOUT), - )) -} - -/// Drives the swarm: dials what `commands` ask for and notes where we listen, until the -/// transport is dropped. -/// How a node relates to relays. -struct Relaying { - /// It relays for others. - serving: bool, - /// Relays to use are configured: it doesn't pick any. - configured: bool, - /// Public relays may be picked, after members. - public: bool, - local: PeerId, -} - -/// The relays to pick among `offers`, if this node needs relays, keeping `using`: a -/// node needs them when it has no address others could dial (`direct`), or AutoNAT says -/// it can't be dialled; up to `AUTO_RELAYS`, in an order of its own (the lowest hash of -/// both peer IDs), so that not every node picks the same. -fn relay_check( - local: PeerId, - direct: bool, - nat: &::libp2p::autonat::NatStatus, - offers: &HashMap<PeerId, Multiaddr>, - using: &[PeerId], -) -> Vec<(PeerId, Multiaddr)> { - use ::libp2p::autonat::NatStatus; - let needed = match nat { - NatStatus::Private => true, - NatStatus::Public(_) => false, - NatStatus::Unknown => !direct, - }; - if !needed || using.len() >= AUTO_RELAYS { - return Vec::new(); - } - let score = |relay: &PeerId| { - use std::hash::{Hash, Hasher}; - let mut hasher = std::collections::hash_map::DefaultHasher::new(); - (local, relay).hash(&mut hasher); - hasher.finish() - }; - let mut candidates: Vec<(PeerId, Multiaddr)> = offers - .iter() - .filter(|(relay, _)| **relay != local && !using.contains(relay)) - .map(|(relay, address)| (*relay, address.clone())) - .collect(); - candidates.sort_by_key(|(relay, _)| score(relay)); - candidates.truncate(AUTO_RELAYS - using.len()); - candidates -} - -/// Reserves slots on the relays `relay_check` picks among the members, and lets those -/// picked go once AutoNAT says this node can be dialled. -fn pick_relays( - swarm: &mut Swarm<Behaviour>, - book: &Mutex<Book>, - relaying: &Relaying, - nat: &::libp2p::autonat::NatStatus, - picked: &mut HashMap<::libp2p::core::transport::ListenerId, PeerId>, -) { - if nat.is_public() && !picked.is_empty() { - info!("Reachable directly (AutoNAT); letting the relays picked go"); - let mut book = lock(book); - for (listener, relay) in std::mem::take(picked) { - swarm.remove_listener(listener); - book.slots.remove(&relay); - } - return; - } - let (direct, offers, public) = { - let mut book = lock(book); - book.failed_relays - .retain(|_, at| at.elapsed() < RELAY_PAUSE); - let failed = book.failed_relays.clone(); - let usable = |offers: &HashMap<PeerId, Multiaddr>| -> HashMap<PeerId, Multiaddr> { - offers - .iter() - .filter(|(relay, _)| !failed.contains_key(relay)) - .map(|(relay, address)| (*relay, address.clone())) - .collect() - }; - let public = if relaying.public { - usable(&book.public_relays) - } else { - HashMap::new() - }; - (!book.direct().is_empty(), usable(&book.relays), public) - }; - let mut using: Vec<PeerId> = picked.values().copied().collect(); - // Members first, then public ones for what's left. - let mut wanted = relay_check(relaying.local, direct, nat, &offers, &using); - using.extend(wanted.iter().map(|(relay, _)| *relay)); - wanted.extend(relay_check(relaying.local, direct, nat, &public, &using)); - for (relay, address) in wanted { - match swarm.listen_on(address.clone().with(Protocol::P2pCircuit)) { - Ok(listener) => { - info!(relay = %relay, address = %address, "Picked a member as libp2p relay"); - picked.insert(listener, relay); - } - Err(error) => { - debug!(relay = %relay, error = %error, "Couldn't use a member as libp2p relay"); - } - } - } -} - -/// Asks the DHT (with `--libp2p-public`) where `peer` is, for the next attempt. -fn find_on_dht(swarm: &mut Swarm<Behaviour>, peer: PeerId) { - if let Some(dht) = swarm.behaviour_mut().kad.as_mut() { - dht.get_closest_peers(peer); - } -} - -/// `again`: to schedule commands. -async fn run( - mut swarm: Swarm<Behaviour>, - mut commands: mpsc::UnboundedReceiver<Command>, - again: mpsc::UnboundedSender<Command>, - book: Arc<Mutex<Book>>, - relaying: Relaying, - stopping: watch::Sender<bool>, -) { - let serving = relaying.serving; - let mut nat = ::libp2p::autonat::NatStatus::Unknown; - // Relays picked among the members, by listener. - let mut picked: HashMap<::libp2p::core::transport::ListenerId, PeerId> = HashMap::new(); - let mut check = tokio::time::interval(RELAY_CHECK); - check.set_missed_tick_behavior(tokio::time::MissedTickBehavior::Delay); - let mut dht_bootstrap = tokio::time::interval(DHT_BOOTSTRAP); - dht_bootstrap.set_missed_tick_behavior(tokio::time::MissedTickBehavior::Delay); - // Relays we listen through, by listener: as configured, and their peer. - let mut reservations: HashMap<::libp2p::core::transport::ListenerId, (Multiaddr, PeerId)> = - HashMap::new(); - let reserve_later = |configured: Multiaddr| { - let again = again.clone(); - tokio::spawn(async move { - tokio::time::sleep(RELAY_RETRY).await; - let _ = again.send(Command::Reserve { - relay: configured.clone(), - configured, - }); - }); - }; - let mut connecting: HashMap<PeerId, Vec<oneshot::Sender<Result<(), String>>>> = HashMap::new(); - let mut identifying: HashMap< - ConnectionId, - (Multiaddr, oneshot::Sender<Result<PeerId, String>>), - > = HashMap::new(); - let mut prune = tokio::time::interval(PRUNE_EVERY); - prune.set_missed_tick_behavior(tokio::time::MissedTickBehavior::Delay); - loop { - tokio::select! { - _ = prune.tick() => { - let forgotten = lock(&book).prune(tokio::time::Instant::now(), |peer| swarm.is_connected(peer)); - if forgotten > 0 { - debug!(forgotten, "Forgot libp2p peers nobody mentions any more"); - } - } - _ = dht_bootstrap.tick(), if relaying.public => { - if let Some(dht) = swarm.behaviour_mut().kad.as_mut() - && let Err(error) = dht.bootstrap() - { - warn!(error = %error, "Couldn't join the IPFS DHT"); - } - } - _ = check.tick(), if !relaying.configured => { - pick_relays(&mut swarm, &book, &relaying, &nat, &mut picked); - } - command = commands.recv() => match command { - None => break, - Some(Command::CheckRelays) => { - if !relaying.configured { - pick_relays(&mut swarm, &book, &relaying, &nat, &mut picked); - } - } - Some(Command::Connect { peer, addresses, done }) => { - if swarm.is_connected(&peer) { - let _ = done.send(Ok(())); - continue; - } - let waiting = connecting.entry(peer).or_default(); - waiting.push(done); - if waiting.len() > 1 { - continue; // Already dialing. - } - let mut opts = DialOpts::peer_id(peer) - .addresses(addresses) - .condition(PeerCondition::DisconnectedAndNotDialing); - if relaying.public { - // Addresses the DHT knows too. - opts = opts.extend_addresses_through_behaviour(); - } - if let Err(error) = swarm.dial(opts.build()) { - count_dial_failure(&mut lock(&book).counts.dial_failures, &error); - for done in connecting.remove(&peer).into_iter().flatten() { - let _ = done.send(Err(error.to_string())); - } - find_on_dht(&mut swarm, peer); - } - } - Some(Command::Reserve { relay, configured }) if split_peer(&relay).is_none() => { - // Which peer relays there first. - let again = again.clone(); - tokio::spawn(async move { - let (done, identified) = oneshot::channel(); - if again - .send(Command::Identify { address: relay.clone(), done }) - .is_err() - { - return; - } - match tokio::time::timeout(CONNECT_TIMEOUT, identified).await { - Ok(Ok(Ok(peer))) => { - if let Ok(relay) = relay.with_p2p(peer) { - let _ = again.send(Command::Reserve { relay, configured }); - } - } - _ => { - warn!(relay = %relay, "Couldn't reach a libp2p relay; trying again later"); - tokio::time::sleep(RELAY_RETRY).await; - let _ = again.send(Command::Reserve { relay, configured }); - } - } - }); - } - Some(Command::Reserve { relay, configured }) => { - let Some(relay_peer) = split_peer(&relay) else { - continue; // The arm above takes those. - }; - match swarm.listen_on(relay.clone().with(Protocol::P2pCircuit)) { - Ok(listener) => { - debug!(relay = %relay, "Reserving a slot on a libp2p relay"); - reservations.insert(listener, (configured, relay_peer)); - } - Err(error) => { - warn!(relay = %relay, error = %error, "Couldn't use a libp2p relay; trying again later"); - reserve_later(configured); - } - } - } - Some(Command::Identify { address, done }) => { - let opts = DialOpts::unknown_peer_id().address(address.clone()).build(); - let id = opts.connection_id(); - match swarm.dial(opts) { - Ok(()) => { - identifying.insert(id, (address, done)); - } - Err(error) => { - let _ = done.send(Err(error.to_string())); - } - } - } - }, - event = swarm.select_next_some() => match event { - SwarmEvent::ConnectionEstablished { peer_id, connection_id, endpoint, .. } => { - { - let mut book = lock(&book); - book.touch(peer_id); - let relayed = endpoint.is_relayed(); - book.connections.insert(connection_id, (peer_id, relayed)); - debug!( - peer = %peer_id, - connection = %connection_id, - dialled = endpoint.is_dialer(), - address = %endpoint.get_remote_address(), - relayed, - "libp2p connection opened" - ); - } - for done in connecting.remove(&peer_id).into_iter().flatten() { - let _ = done.send(Ok(())); - } - if let Some((address, done)) = identifying.remove(&connection_id) { - lock(&book).remember(peer_id, address); - let _ = done.send(Ok(peer_id)); - } - } - SwarmEvent::ConnectionClosed { peer_id, connection_id, cause, .. } => { - lock(&book).connections.remove(&connection_id); - debug!( - peer = %peer_id, - connection = %connection_id, - cause = ?cause, - "libp2p connection closed" - ); - } - SwarmEvent::OutgoingConnectionError { connection_id, peer_id, error } => { - count_dial_failure(&mut lock(&book).counts.dial_failures, &error); - if let Some((_, done)) = identifying.remove(&connection_id) { - let _ = done.send(Err(error.to_string())); - } - if let Some(peer) = peer_id - && !swarm.is_connected(&peer) - { - if let Some(waiting) = connecting.remove(&peer) { - for done in waiting { - let _ = done.send(Err(error.to_string())); - } - find_on_dht(&mut swarm, peer); - } - } - } - SwarmEvent::NewListenAddr { address, .. } => { - info!(address = %address, "libp2p listening"); - // A relay tells those reserving where it is: its external addresses. - if serving && !is_local(&address) && !is_relayed(&address) { - swarm.add_external_address(address.clone()); - } - let mut book = lock(&book); - if !book.listening.contains(&address) { - book.listening.push(address); - } - } - SwarmEvent::ExpiredListenAddr { address, .. } => { - info!(address = %address, "libp2p no longer listening"); - if serving { - swarm.remove_external_address(&address); - } - lock(&book).listening.retain(|known| *known != address); - } - SwarmEvent::ListenerClosed { listener_id, addresses, reason } => { - lock(&book) - .listening - .retain(|known| !addresses.contains(known)); - if let Some((relay, relay_peer)) = reservations.remove(&listener_id) { - { - let mut book = lock(&book); - if book.slots.remove(&relay_peer) { - book.counts.slots_lost += 1; - } else { - book.counts.slots_not_granted += 1; - } - } - warn!(relay = %relay, reason = ?reason, "Lost the slot on a libp2p relay; reserving again later"); - reserve_later(relay); - } - // A relay picked among the members: the next check picks again, another - // one if this one never granted the slot. - if let Some(relay) = picked.remove(&listener_id) { - let lost = { - let mut book = lock(&book); - let lost = book.slots.remove(&relay); - if lost { - book.counts.slots_lost += 1; - } else { - book.counts.slots_not_granted += 1; - book.failed_relays.insert(relay, tokio::time::Instant::now()); - } - lost - }; - if lost { - debug!(relay = %relay, reason = ?reason, "Lost the slot on a member relaying"); - } else { - info!( - relay = %relay, - pause = ?RELAY_PAUSE, - "A relay didn't grant a slot (unreachable, or another peer at its address); picking others for a while" - ); - } - } - } - SwarmEvent::ListenerError { error, .. } => { - warn!(error = %error, "libp2p listener failed"); - } - SwarmEvent::Behaviour(BehaviourEvent::RelayClient( - ::libp2p::relay::client::Event::ReservationReqAccepted { relay_peer_id, renewal, .. }, - )) => { - { - let mut book = lock(&book); - book.slots.insert(relay_peer_id); - book.failed_relays.remove(&relay_peer_id); - if !renewal { - book.counts.slots_granted += 1; - } - } - if !renewal { - info!(relay = %relay_peer_id, "Reachable through a libp2p relay"); - } - } - SwarmEvent::Behaviour(BehaviourEvent::Autonat( - ::libp2p::autonat::Event::StatusChanged { old, new }, - )) => { - info!(old = ?old, new = ?new, "libp2p reachability (AutoNAT)"); - { - use ::libp2p::autonat::NatStatus; - let mut book = lock(&book); - (book.reachability, book.public_address) = match &new { - NatStatus::Unknown => (Reachability::Unknown, None), - NatStatus::Private => (Reachability::Private, None), - NatStatus::Public(address) => { - (Reachability::Public, Some(address.clone())) - } - }; - } - nat = new; - } - SwarmEvent::Behaviour(BehaviourEvent::Relay(event)) => { - debug!(event = ?event, "libp2p relay"); - } - SwarmEvent::Behaviour(BehaviourEvent::Dcutr(event)) => match event.result { - Ok(_) => { - lock(&book).counts.hole_punches.succeeded += 1; - info!(peer = %event.remote_peer_id, "Connected directly to a peer behind a relay"); - } - Err(error) => { - lock(&book).counts.hole_punches.failed += 1; - debug!(peer = %event.remote_peer_id, error = %error, "Couldn't connect directly to a peer behind a relay; the relay carries on"); - } - }, - SwarmEvent::Behaviour(BehaviourEvent::Identify( - ::libp2p::identify::Event::Received { connection_id, peer_id, info }, - )) => { - let mut book = lock(&book); - let listen = published(&info.listen_addrs); - // Every new connection identifies again: logged when it says something new. - if book.knows(peer_id, &listen) { - trace!(peer = %peer_id, connection = %connection_id, "libp2p peer identified again"); - } else { - debug!( - peer = %peer_id, - connection = %connection_id, - listen = ?info.listen_addrs, - observed = %info.observed_addr, - agent = %info.agent_version, - "libp2p peer identified" - ); - } - // Last first: `remember` puts each in front. - for address in listen.into_iter().rev() { - book.remember(peer_id, address); - } - if relaying.public - && info.protocols.contains(&::libp2p::relay::HOP_PROTOCOL_NAME) - && (book.public_relays.len() < MAX_PEERS - || book.public_relays.contains_key(&peer_id)) - && let Some(address) = book - .addresses - .get(&peer_id) - .and_then(|known| known.first()) - .and_then(|address| address.clone().with_p2p(peer_id).ok()) - { - book.public_relays.insert(peer_id, address); - } - if info.protocols.contains(&PROTOCOL) { - book.continuum.insert(peer_id); - if book.lan.remove(&peer_id) { - book.discover(peer_id); - } - } - } - SwarmEvent::Behaviour(BehaviourEvent::Mdns( - ::libp2p::mdns::Event::Discovered(found), - )) => { - for (peer, address) in found { - if peer == relaying.local { - continue; - } - debug!(peer = %peer, address = %address, "libp2p peer on the LAN"); - let continuum = { - let mut book = lock(&book); - book.remember(peer, address.clone()); - book.continuum.contains(&peer) - }; - if continuum { - lock(&book).discover(peer); - } else if lock(&book).lan.len() < MAX_PEERS { - // Connected, identify says whether it speaks continuum. - lock(&book).lan.insert(peer); - let _ = swarm.dial( - DialOpts::peer_id(peer) - .addresses(vec![address]) - .condition(PeerCondition::DisconnectedAndNotDialing) - .build(), - ); - } - } - } - _ => {} - }, - } - } - let _ = stopping.send(true); -} - -/// One message from an inbound stream. -async fn read_message(mut stream: ::libp2p::Stream) -> Result<Vec<u8>> { - let mut length = [0u8; 4]; - tokio::time::timeout(STREAM_TIMEOUT, stream.read_exact(&mut length)) - .await - .map_err(|_| anyhow!("no length within {STREAM_TIMEOUT:?}"))??; - let length = u32::from_be_bytes(length) as usize; - if length > MAX_MESSAGE { - bail!("a message of {length} bytes; at most {MAX_MESSAGE} are read"); - } - let mut body = vec![0u8; length]; - tokio::time::timeout(stream_timeout(length), stream.read_exact(&mut body)) - .await - .map_err(|_| { - anyhow!( - "{length} bytes took longer than {:?}", - stream_timeout(length) - ) - })??; - Ok(body) -} - -#[async_trait] -impl Transport for Libp2pTransport { - fn local_id(&self) -> &str { - &self.local_id - } - - fn is_peer_id(&self, id: &str) -> bool { - PeerId::from_str(id).is_ok() - } - - /// The longest a message may take on a stream. - fn delivery_limit(&self) -> Duration { - stream_timeout(MAX_MESSAGE) - } - - /// Where we can be reached, each with our peer ID: the announced addresses, or else - /// those we listen on (`published`), and those through relays. A relay adds each - /// direct one again, ending in `/p2p-circuit`: where to reserve a slot. - fn local_addresses(&self) -> Vec<String> { - let book = lock(&self.book); - let direct: Vec<Multiaddr> = book - .direct() - .into_iter() - .filter_map(|address| address.with_p2p(self.peer_id).ok()) - .collect(); - let relayed = book - .listening - .iter() - .filter(|address| is_relayed(address)) - .filter_map(|address| address.clone().with_p2p(self.peer_id).ok()); - let offers: Vec<Multiaddr> = if book.serving { - direct - .iter() - .map(|address| address.clone().with(Protocol::P2pCircuit)) - .collect() - } else { - Vec::new() - }; - direct - .into_iter() - .chain(relayed) - .chain(offers) - .map(|address| address.to_string()) - .collect() - } - - /// A peer ID, or a multiaddr ending in one (noted as where that peer is). - fn locate(&self, target: &str) -> Option<String> { - if let Ok(peer) = PeerId::from_str(target) { - return Some(peer.to_string()); - } - let mut address = Multiaddr::from_str(target).ok()?; - // A relay saying where to reserve a slot: `<address>/p2p/<relay>/p2p-circuit`. - if let Some(Protocol::P2pCircuit) = address.iter().last() { - address.pop(); - let relay = split_peer(&address)?; - if relay != self.peer_id { - let new = { - let mut book = lock(&self.book); - let new = book.relays.get(&relay) != Some(&address); - if new && (book.relays.len() < MAX_PEERS || book.relays.contains_key(&relay)) { - book.relays.insert(relay, address.clone()); - } - book.remember(relay, address); - new - }; - if new { - let _ = self.commands.send(Command::CheckRelays); - } - } - return Some(relay.to_string()); - } - let peer = split_peer(&address)?; - if peer != self.peer_id { - lock(&self.book).remember(peer, address); - } - Some(peer.to_string()) - } - - fn connection(&self, target: &str) -> Option<Connection> { - let peer = PeerId::from_str(target).ok()?; - lock(&self.book).connection(&peer) - } - - fn stats(&self) -> TransportStats { - TransportStats { - libp2p: Some(lock(&self.book).stats()), - ..TransportStats::default() - } - } - - /// Nodes found on the LAN (mDNS) that speak continuum. - fn discovered_seeds(&self) -> Vec<String> { - std::mem::take(&mut lock(&self.book).discovered) - .iter() - .map(Multiaddr::to_string) - .collect() - } - - /// Where `target` is, each address with its peer ID. - fn locations(&self, target: &str) -> Vec<String> { - let Ok(peer) = PeerId::from_str(target) else { - return Vec::new(); - }; - lock(&self.book) - .addresses - .get(&peer) - .into_iter() - .flatten() - .filter_map(|address| address.clone().with_p2p(peer).ok()) - .map(|address| address.to_string()) - .collect() - } - - /// A multiaddr ending in a peer ID is that peer; one without is connected to, to - /// find out. A bare peer ID resolves if this transport knows where it is. - async fn resolve_seed(&self, seed: &str) -> Result<String> { - if let Ok(peer) = PeerId::from_str(seed) { - if lock(&self.book).addresses.contains_key(&peer) { - return Ok(peer.to_string()); - } - bail!("no address known for libp2p peer {peer}; give a multiaddr"); - } - let address = - Multiaddr::from_str(seed).with_context(|| format!("{seed} is no multiaddr"))?; - if let Some(peer) = self.locate(seed) { - return Ok(peer); - } - let (done, identified) = oneshot::channel(); - self.commands - .send(Command::Identify { address, done }) - .map_err(|_| anyhow!("the libp2p swarm stopped"))?; - match tokio::time::timeout(CONNECT_TIMEOUT, identified).await { - Ok(Ok(Ok(peer))) => Ok(peer.to_string()), - Ok(Ok(Err(error))) => bail!("couldn't connect to {seed}: {error}"), - Ok(Err(_)) => bail!("the libp2p swarm stopped"), - Err(_) => bail!("connecting to {seed} took longer than {CONNECT_TIMEOUT:?}"), - } - } - - fn encode(&self, peer: &str, message: &ParsedMessage) -> Result<EncodedMessage> { - let body = wire::encode(message)?; - Ok(EncodedMessage { - peer: peer.to_owned(), - address: peer.to_owned(), - payload_len: body.len(), - body: body.into(), - kind: message.kind(), - message: None, - }) - } - - async fn send_encoded(&self, message: &EncodedMessage) -> Result<()> { - let peer = PeerId::from_str(&message.peer) - .with_context(|| format!("{} is no libp2p peer ID", message.peer))?; - self.connect(peer).await?; - let mut control = self.control.clone(); - let body = message.body.clone(); - let write = async move { - let mut stream = control.open_stream(peer, PROTOCOL).await?; - stream.write_all(&(body.len() as u32).to_be_bytes()).await?; - stream.write_all(&body).await?; - stream.close().await?; - Ok::<(), anyhow::Error>(()) - }; - let timeout = stream_timeout(message.body.len()); - tokio::time::timeout(timeout, write) - .await - .map_err(|_| anyhow!("sending to {peer} took longer than {timeout:?}"))? - .with_context(|| format!("Sending to {peer}")) - } - - /// Reads inbound streams (`READS` at once) and handles their messages one at a - /// time, in the order they were read. - async fn start_consumer(&self, handler: MessageHandler) -> Result<()> { - let Some(mut incoming) = self.incoming.lock().await.take() else { - bail!("libp2p consumer already started"); - }; - let (sender, mut received) = mpsc::channel::<(PeerId, Vec<u8>)>(READS); - let reads = Arc::new(Semaphore::new(READS)); - tokio::spawn(async move { - while let Some((peer, stream)) = incoming.next().await { - let Ok(permit) = Arc::clone(&reads).acquire_owned().await else { - break; - }; - let sender = sender.clone(); - tokio::spawn(async move { - match read_message(stream).await { - Ok(body) => { - let _ = sender.send((peer, body)).await; - } - Err(error) => { - debug!(peer = %peer, error = %format!("{error:#}"), "Dropping an unreadable libp2p stream"); - } - } - drop(permit); - }); - } - }); - while let Some((peer, body)) = received.recv().await { - match wire::decode(&body) { - Ok(message) => { - if let Err(error) = handler(peer.to_string(), message, body.len()).await { - warn!(peer = %peer, error = %format!("{error:#}"), "Failed to process inbound message"); - } - } - Err(error) => { - debug!(peer = %peer, error = %error, "Dropping a libp2p message that doesn't decode"); - } - } - } - Ok(()) - } - - async fn wait_for_exit(&self) -> std::io::Result<std::process::ExitStatus> { - let mut stopped = self.stopped.clone(); - let _ = stopped.wait_for(|stopped| *stopped).await; - Err(std::io::Error::other("the libp2p swarm stopped")) - } -} - -#[cfg(test)] -mod tests { - use std::sync::atomic::{AtomicU64, Ordering}; - - use super::*; - use crate::document::replica::Epoch; - use crate::transport::{HeadsSummary, Status}; - - /// Memory ports are process-wide. - static NEXT_PORT: AtomicU64 = AtomicU64::new(40_000); - - /// A node on the in-memory transport, listening on a port of its own (or nowhere), - /// and its address with its peer ID (or just its peer ID). - fn memory_node_with( - listen: bool, - relays: Vec<Multiaddr>, - relay: bool, - ) -> (Libp2pTransport, Multiaddr) { - let port = NEXT_PORT.fetch_add(1, Ordering::Relaxed); - let key = Keypair::generate_ed25519(); - let address: Multiaddr = format!("/memory/{port}").parse().unwrap(); - let peer = key.public().to_peer_id(); - let transport = Libp2pTransport::start(Libp2pConfig { - key, - listen: if listen { - vec![address.clone()] - } else { - Vec::new() - }, - announce: Vec::new(), - relays, - relay, - mdns: false, - public: false, - memory: true, - }) - .unwrap(); - let address = if listen { - address.with_p2p(peer).unwrap() - } else { - Multiaddr::empty().with(Protocol::P2p(peer)) - }; - (transport, address) - } - - fn memory_node() -> (Libp2pTransport, Multiaddr) { - memory_node_with(true, Vec::new(), false) - } - - fn status() -> ParsedMessage { - ParsedMessage::Status(Status { - heads: HeadsSummary::of(Vec::new()), - epoch: Epoch::GENESIS, - epoch_seq: 3, - ready: true, - syncs_with_you: false, - }) - } - - /// Starts `transport`'s consumer, forwarding what it receives. - fn received( - transport: Arc<Libp2pTransport>, - ) -> mpsc::UnboundedReceiver<(String, ParsedMessage)> { - let (sender, receiver) = mpsc::unbounded_channel(); - tokio::spawn(async move { - transport - .start_consumer(Box::new(move |from, message, _| { - let sender = sender.clone(); - Box::pin(async move { - let _ = sender.send((from, message)); - Ok(()) - }) - })) - .await - }); - receiver - } - - #[tokio::test] - async fn messages_both_ways_over_one_connection() { - let (a, a_address) = memory_node(); - let (b, _) = memory_node(); - let (a, b) = (Arc::new(a), Arc::new(b)); - let mut at_a = received(Arc::clone(&a)); - let mut at_b = received(Arc::clone(&b)); - - assert_eq!( - b.resolve_seed(&a_address.to_string()).await.unwrap(), - a.local_id() - ); - b.send_message(a.local_id(), &status()).await.unwrap(); - let (from, message) = at_a.recv().await.unwrap(); - assert_eq!(from, b.local_id()); - assert!(matches!(message, ParsedMessage::Status(status) if status.epoch_seq == 3)); - - // a knows no address of b, but b's connection is there. - a.send_message(b.local_id(), &status()).await.unwrap(); - let (from, _) = at_b.recv().await.unwrap(); - assert_eq!(from, a.local_id()); - - assert_eq!(a.connection(b.local_id()), Some(Connection::Direct)); - assert_eq!(b.connection(a.local_id()), Some(Connection::Direct)); - let stats = a.stats().libp2p.unwrap(); - assert!(stats.connections.direct >= 1); - assert_eq!(stats.connections.relayed, 0); - } - - #[tokio::test] - async fn a_seed_without_a_peer_id_is_connected_to_to_find_out() { - let (a, a_address) = memory_node(); - let (b, _) = memory_node(); - let mut bare = a_address.clone(); - bare.pop(); - assert_eq!( - b.resolve_seed(&bare.to_string()).await.unwrap(), - a.local_id() - ); - // And b now knows where a is. - assert_eq!(b.locations(a.local_id()), [a_address.to_string()]); - } - - #[tokio::test] - async fn listen_addresses_carry_the_peer_id() { - let (a, a_address) = memory_node(); - let deadline = tokio::time::Instant::now() + Duration::from_secs(5); - while a.local_addresses().is_empty() && tokio::time::Instant::now() < deadline { - tokio::time::sleep(Duration::from_millis(10)).await; - } - assert_eq!(a.local_addresses(), [a_address.to_string()]); - assert_eq!( - a.locate(&a_address.to_string()).as_deref(), - Some(a.local_id()) - ); - } - - /// Waits up to 5 s for `condition`. - async fn eventually(mut condition: impl FnMut() -> bool) -> bool { - let deadline = tokio::time::Instant::now() + Duration::from_secs(5); - while !condition() { - if tokio::time::Instant::now() >= deadline { - return false; - } - tokio::time::sleep(Duration::from_millis(10)).await; - } - true - } - - /// A node learns where a peer that dialled it listens (identify), and can then - /// pass it on. - #[tokio::test] - async fn a_dialled_node_learns_where_the_dialler_listens() { - let (a, a_address) = memory_node(); - let (b, b_address) = memory_node(); - let (a, b) = (Arc::new(a), Arc::new(b)); - let _at_a = received(Arc::clone(&a)); - b.resolve_seed(&a_address.to_string()).await.unwrap(); - b.send_message(a.local_id(), &status()).await.unwrap(); - let b_id = b.local_id().to_owned(); - assert!( - eventually(|| a.locations(&b_id) == [b_address.to_string()]).await, - "a knows {:?} of b", - a.locations(&b_id) - ); - } - - #[tokio::test] - async fn announced_addresses_are_published_instead() { - let key = Keypair::generate_ed25519(); - let peer = key.public().to_peer_id(); - let port = NEXT_PORT.fetch_add(1, Ordering::Relaxed); - let announced: Multiaddr = "/ip4/203.0.113.7/tcp/9661".parse().unwrap(); - let transport = Libp2pTransport::start(Libp2pConfig { - key, - listen: vec![format!("/memory/{port}").parse().unwrap()], - announce: vec![announced.clone()], - relays: Vec::new(), - relay: false, - mdns: false, - public: false, - memory: true, - }) - .unwrap(); - assert_eq!( - transport.local_addresses(), - [announced.with_p2p(peer).unwrap().to_string()] - ); - } - - #[test] - fn local_addresses_are_left_out_unless_there_are_only_local_ones() { - let parse = |text: &str| text.parse::<Multiaddr>().unwrap(); - let loopback = parse("/ip4/127.0.0.1/tcp/1"); - let link = parse("/ip6/fe80::1/tcp/1"); - let lan = parse("/ip4/192.168.1.2/tcp/1"); - let wireguard = parse("/ip6/fd00::2/tcp/1"); - assert_eq!( - published(&[ - loopback.clone(), - link.clone(), - lan.clone(), - wireguard.clone() - ]), - [lan, wireguard] - ); - assert_eq!( - published(&[loopback.clone(), link.clone()]), - [loopback, link] - ); - } - - /// b listens nowhere but through the relay r; a reaches it there. - #[tokio::test] - async fn a_node_nobody_can_dial_is_reached_through_a_relay() { - let (_r, r_address) = memory_node_with(true, Vec::new(), true); - let (b, _) = memory_node_with(false, vec![r_address.clone()], false); - let b = Arc::new(b); - let mut at_b = received(Arc::clone(&b)); - assert!( - eventually(|| !b.local_addresses().is_empty()).await, - "b got no slot on the relay" - ); - let relayed = b.local_addresses()[0].clone(); - assert!( - relayed.starts_with(&format!("{r_address}/p2p-circuit/")), - "{relayed}" - ); - - assert!(eventually(|| b.stats().libp2p.unwrap().relay_slots.held == 1).await); - let slots = b.stats().libp2p.unwrap().relay_slots; - assert_eq!((slots.granted, slots.not_granted), (1, 0)); - - let (a, _) = memory_node(); - assert_eq!(a.resolve_seed(&relayed).await.unwrap(), b.local_id()); - a.send_message(b.local_id(), &status()).await.unwrap(); - let (from, _) = at_b.recv().await.unwrap(); - assert_eq!(from, a.local_id()); - assert!(a.connection(b.local_id()).is_some()); - } - - fn peer() -> PeerId { - Keypair::generate_ed25519().public().to_peer_id() - } - - #[test] - fn relays_are_picked_when_needed() { - use ::libp2p::autonat::NatStatus; - let local = peer(); - let offers: HashMap<PeerId, Multiaddr> = (0..4) - .map(|port| (peer(), format!("/memory/{port}").parse().unwrap())) - .collect(); - let check = |direct, nat: &NatStatus, using: &[PeerId]| { - relay_check(local, direct, nat, &offers, using) - }; - // Dialable, or not known yet with an address to dial: none. - assert!(check(true, &NatStatus::Public(Multiaddr::empty()), &[]).is_empty()); - assert!(check(false, &NatStatus::Public(Multiaddr::empty()), &[]).is_empty()); - assert!(check(true, &NatStatus::Unknown, &[]).is_empty()); - // No address to dial, or AutoNAT says it can't be dialled: some. - assert_eq!(check(false, &NatStatus::Unknown, &[]).len(), AUTO_RELAYS); - let picked = check(true, &NatStatus::Private, &[]); - assert_eq!(picked.len(), AUTO_RELAYS); - // One in use: the next in the same order. - let more = check(true, &NatStatus::Private, &[picked[0].0]); - assert_eq!(more.len(), AUTO_RELAYS - 1); - assert_eq!(more[0].0, picked[1].0); - let all: Vec<PeerId> = picked.iter().map(|(relay, _)| *relay).collect(); - assert!(check(true, &NatStatus::Private, &all).is_empty()); - // Never itself. - let only_us = HashMap::from([(local, Multiaddr::empty())]); - assert!(relay_check(local, false, &NatStatus::Private, &only_us, &[]).is_empty()); - } - - /// A relay says so in its addresses; b, which nobody can dial, learns of it (as from - /// the member list) and becomes reachable through it. - #[tokio::test] - async fn a_member_that_relays_is_picked() { - let (r, _) = memory_node_with(true, Vec::new(), true); - assert!(eventually(|| !r.local_addresses().is_empty()).await); - let offer = r - .local_addresses() - .into_iter() - .find(|address| address.ends_with("/p2p-circuit")) - .expect("the relay offers itself"); - let (b, _) = memory_node_with(false, Vec::new(), false); - assert_eq!(b.locate(&offer).as_deref(), Some(r.local_id())); - assert!( - eventually(|| b - .local_addresses() - .iter() - .any(|address| address.contains("/p2p-circuit/"))) - .await, - "b isn't reachable through r: {:?}", - b.local_addresses() - ); - } - - /// A peer on the LAN that speaks continuum becomes a seed once, at its address. - #[test] - fn lan_peers_become_seeds_once() { - let mut book = Book::default(); - let lan = peer(); - let address: Multiaddr = "/ip4/192.168.1.5/tcp/9661".parse().unwrap(); - book.discover(lan); // No address known: nothing. - assert!(book.discovered.is_empty()); - book.remember(lan, address.clone()); - book.discover(lan); - book.discover(lan); - assert_eq!(book.discovered, [address.with_p2p(lan).unwrap()]); - } - - #[test] - fn known_addresses() { - let mut book = Book::default(); - let (relay, us) = (peer(), peer()); - let direct: Multiaddr = "/ip6/fd00::1/tcp/9661".parse().unwrap(); - let relayed: Multiaddr = format!("/ip6/fd00::2/tcp/9661/p2p/{relay}/p2p-circuit/p2p/{us}") - .parse() - .unwrap(); - assert!(!book.knows(us, &[direct.clone()])); - book.remember(us, relayed.clone()); - book.remember(us, direct.clone()); - // In any order, with or without the peer ID. - assert!(book.knows(us, &[relayed.clone(), direct.clone()])); - assert!(book.knows(us, &[direct.clone().with_p2p(us).unwrap()])); - assert!(!book.knows(us, &["/ip6/fd00::3/tcp/9661".parse().unwrap()])); - } - - /// Peers nobody mentions any more are forgotten, but connected ones. - #[test] - fn stale_peers_are_forgotten() { - let start = tokio::time::Instant::now(); - let (old, current, connected) = (peer(), peer(), peer()); - let address: Multiaddr = "/ip6/fd00::1/tcp/9661".parse().unwrap(); - let mut book = Book::default(); - for peer in [old, current, connected] { - book.remember(peer, address.clone()); - } - book.relays.insert(old, address.clone()); - book.continuum.insert(old); - let later = start + STALE_AFTER; - // `current` was mentioned again since. - book.seen.insert(current, later); - assert_eq!(book.prune(later, |peer| *peer == connected), 1); - assert!(!book.addresses.contains_key(&old)); - assert!(!book.relays.contains_key(&old) && !book.continuum.contains(&old)); - assert!(book.addresses.contains_key(¤t)); - assert!(book.addresses.contains_key(&connected)); - assert_eq!(book.prune(later, |_| false), 1); // `connected`, once it isn't. - } - - /// A relay doesn't dial the nodes it relays for through itself. - #[test] - fn no_circuits_through_ourselves() { - let (us, other_relay, target) = (peer(), peer(), peer()); - let through = |relay: PeerId| -> Multiaddr { - format!("/ip6/fd00::1/tcp/9661/p2p/{relay}/p2p-circuit") - .parse() - .unwrap() - }; - let direct: Multiaddr = "/ip6/fd00::2/tcp/9661".parse().unwrap(); - assert_eq!(relay_of(&through(us)), Some(us)); - assert_eq!(relay_of(&direct), None); - assert_eq!(relay_of(&direct.clone().with_p2p(target).unwrap()), None); - assert_eq!( - dialable(&[through(us), through(other_relay), direct.clone()], us), - [through(other_relay), direct] - ); - } - - #[tokio::test] - async fn unknown_peers_are_refused() { - let (b, _) = memory_node(); - let stranger = Keypair::generate_ed25519() - .public() - .to_peer_id() - .to_string(); - assert!(b.send_message(&stranger, &status()).await.is_err()); - assert!(b.resolve_seed(&stranger).await.is_err()); - assert_eq!(b.connection(&stranger), None); - } - - #[test] - fn a_direct_connection_wins_over_a_relayed_one() { - let mut book = Book::default(); - let (relayed_only, both) = (peer(), peer()); - let mut id = 0; - let mut connect = |book: &mut Book, peer: PeerId, relayed: bool| { - id += 1; - book.connections - .insert(ConnectionId::new_unchecked(id), (peer, relayed)); - }; - connect(&mut book, relayed_only, true); - connect(&mut book, both, true); - connect(&mut book, both, false); - assert_eq!(book.connection(&relayed_only), Some(Connection::Relayed)); - assert_eq!(book.connection(&both), Some(Connection::Direct)); - assert_eq!(book.connection(&peer()), None); - let connections = book.stats().connections; - assert_eq!((connections.direct, connections.relayed), (1, 2)); - } -} |