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-rw-r--r--p2p/src/discovery/lookup.rs366
-rw-r--r--p2p/src/discovery/mod.rs262
-rw-r--r--p2p/src/discovery/refresh.rs289
3 files changed, 917 insertions, 0 deletions
diff --git a/p2p/src/discovery/lookup.rs b/p2p/src/discovery/lookup.rs
new file mode 100644
index 0000000..f404133
--- /dev/null
+++ b/p2p/src/discovery/lookup.rs
@@ -0,0 +1,366 @@
+use std::{sync::Arc, time::Duration};
+
+use futures_util::{stream::FuturesUnordered, StreamExt};
+use log::{error, trace};
+use rand::{rngs::OsRng, seq::SliceRandom, RngCore};
+use smol::lock::{Mutex, RwLock};
+
+use karyons_core::{async_utils::timeout, utils::decode, Executor};
+
+use karyons_net::{Conn, Endpoint};
+
+use crate::{
+ io_codec::IOCodec,
+ message::{
+ get_msg_payload, FindPeerMsg, NetMsg, NetMsgCmd, PeerMsg, PeersMsg, PingMsg, PongMsg,
+ ShutdownMsg,
+ },
+ monitor::{ConnEvent, DiscoveryEvent, Monitor},
+ net::{ConnectionSlots, Connector, Listener},
+ routing_table::RoutingTable,
+ utils::version_match,
+ Config, Error, PeerID, Result,
+};
+
+/// Maximum number of peers that can be returned in a PeersMsg.
+pub const MAX_PEERS_IN_PEERSMSG: usize = 10;
+
+pub struct LookupService {
+ /// Peer's ID
+ id: PeerID,
+
+ /// Routing Table
+ table: Arc<Mutex<RoutingTable>>,
+
+ /// Listener
+ listener: Arc<Listener>,
+ /// Connector
+ connector: Arc<Connector>,
+
+ /// Outbound slots.
+ outbound_slots: Arc<ConnectionSlots>,
+
+ /// Resolved listen endpoint
+ listen_endpoint: Option<RwLock<Endpoint>>,
+
+ /// Holds the configuration for the P2P network.
+ config: Arc<Config>,
+
+ /// Responsible for network and system monitoring.
+ monitor: Arc<Monitor>,
+}
+
+impl LookupService {
+ /// Creates a new lookup service
+ pub fn new(
+ id: &PeerID,
+ table: Arc<Mutex<RoutingTable>>,
+ config: Arc<Config>,
+ monitor: Arc<Monitor>,
+ ) -> Self {
+ let inbound_slots = Arc::new(ConnectionSlots::new(config.lookup_inbound_slots));
+ let outbound_slots = Arc::new(ConnectionSlots::new(config.lookup_outbound_slots));
+
+ let listener = Listener::new(inbound_slots.clone(), monitor.clone());
+ let connector = Connector::new(
+ config.lookup_connect_retries,
+ outbound_slots.clone(),
+ monitor.clone(),
+ );
+
+ let listen_endpoint = config
+ .listen_endpoint
+ .as_ref()
+ .map(|endpoint| RwLock::new(endpoint.clone()));
+
+ Self {
+ id: id.clone(),
+ table,
+ listener,
+ connector,
+ outbound_slots,
+ listen_endpoint,
+ config,
+ monitor,
+ }
+ }
+
+ /// Start the lookup service.
+ pub async fn start(self: &Arc<Self>, ex: Executor<'_>) -> Result<()> {
+ self.start_listener(ex).await?;
+ Ok(())
+ }
+
+ /// Set the resolved listen endpoint.
+ pub async fn set_listen_endpoint(&self, resolved_endpoint: &Endpoint) {
+ if let Some(endpoint) = &self.listen_endpoint {
+ *endpoint.write().await = resolved_endpoint.clone();
+ }
+ }
+
+ /// Shuts down the lookup service.
+ pub async fn shutdown(&self) {
+ self.connector.shutdown().await;
+ self.listener.shutdown().await;
+ }
+
+ /// Starts iterative lookup and populate the routing table.
+ ///
+ /// This method begins by generating a random peer ID and connecting to the
+ /// provided endpoint. It then sends a FindPeer message containing the
+ /// randomly generated peer ID. Upon receiving peers from the initial lookup,
+ /// it starts connecting to these received peers and sends them a FindPeer
+ /// message that contains our own peer ID.
+ pub async fn start_lookup(&self, endpoint: &Endpoint) -> Result<()> {
+ trace!("Lookup started {endpoint}");
+ self.monitor
+ .notify(&DiscoveryEvent::LookupStarted(endpoint.clone()).into())
+ .await;
+
+ let mut random_peers = vec![];
+ if let Err(err) = self.random_lookup(endpoint, &mut random_peers).await {
+ self.monitor
+ .notify(&DiscoveryEvent::LookupFailed(endpoint.clone()).into())
+ .await;
+ return Err(err);
+ };
+
+ let mut peer_buffer = vec![];
+ self.self_lookup(&random_peers, &mut peer_buffer).await;
+
+ while peer_buffer.len() < MAX_PEERS_IN_PEERSMSG {
+ match random_peers.pop() {
+ Some(p) => peer_buffer.push(p),
+ None => break,
+ }
+ }
+
+ for peer in peer_buffer.iter() {
+ let mut table = self.table.lock().await;
+ let result = table.add_entry(peer.clone().into());
+ trace!("Add entry {:?}", result);
+ }
+
+ self.monitor
+ .notify(&DiscoveryEvent::LookupSucceeded(endpoint.clone(), peer_buffer.len()).into())
+ .await;
+
+ Ok(())
+ }
+
+ /// Starts a random lookup
+ ///
+ /// This will perfom lookup on a random generated PeerID
+ async fn random_lookup(
+ &self,
+ endpoint: &Endpoint,
+ random_peers: &mut Vec<PeerMsg>,
+ ) -> Result<()> {
+ for _ in 0..2 {
+ let peer_id = PeerID::random();
+ let peers = self.connect(&peer_id, endpoint.clone()).await?;
+ for peer in peers {
+ if random_peers.contains(&peer)
+ || peer.peer_id == self.id
+ || self.table.lock().await.contains_key(&peer.peer_id.0)
+ {
+ continue;
+ }
+
+ random_peers.push(peer);
+ }
+ }
+
+ Ok(())
+ }
+
+ /// Starts a self lookup
+ async fn self_lookup(&self, random_peers: &Vec<PeerMsg>, peer_buffer: &mut Vec<PeerMsg>) {
+ let mut tasks = FuturesUnordered::new();
+ for peer in random_peers.choose_multiple(&mut OsRng, random_peers.len()) {
+ let endpoint = Endpoint::Tcp(peer.addr.clone(), peer.discovery_port);
+ tasks.push(self.connect(&self.id, endpoint))
+ }
+
+ while let Some(result) = tasks.next().await {
+ match result {
+ Ok(peers) => peer_buffer.extend(peers),
+ Err(err) => {
+ error!("Failed to do self lookup: {err}");
+ }
+ }
+ }
+ }
+
+ /// Connects to the given endpoint
+ async fn connect(&self, peer_id: &PeerID, endpoint: Endpoint) -> Result<Vec<PeerMsg>> {
+ let conn = self.connector.connect(&endpoint).await?;
+ let io_codec = IOCodec::new(conn);
+ let result = self.handle_outbound(io_codec, peer_id).await;
+
+ self.monitor
+ .notify(&ConnEvent::Disconnected(endpoint).into())
+ .await;
+ self.outbound_slots.remove().await;
+
+ result
+ }
+
+ /// Handles outbound connection
+ async fn handle_outbound(&self, io_codec: IOCodec, peer_id: &PeerID) -> Result<Vec<PeerMsg>> {
+ trace!("Send Ping msg");
+ self.send_ping_msg(&io_codec).await?;
+
+ trace!("Send FindPeer msg");
+ let peers = self.send_findpeer_msg(&io_codec, peer_id).await?;
+
+ if peers.0.len() >= MAX_PEERS_IN_PEERSMSG {
+ return Err(Error::Lookup("Received too many peers in PeersMsg"));
+ }
+
+ trace!("Send Peer msg");
+ if let Some(endpoint) = &self.listen_endpoint {
+ self.send_peer_msg(&io_codec, endpoint.read().await.clone())
+ .await?;
+ }
+
+ trace!("Send Shutdown msg");
+ self.send_shutdown_msg(&io_codec).await?;
+
+ Ok(peers.0)
+ }
+
+ /// Start a listener.
+ async fn start_listener(self: &Arc<Self>, ex: Executor<'_>) -> Result<()> {
+ let addr = match &self.listen_endpoint {
+ Some(a) => a.read().await.addr()?.clone(),
+ None => return Ok(()),
+ };
+
+ let endpoint = Endpoint::Tcp(addr, self.config.discovery_port);
+
+ let selfc = self.clone();
+ let callback = |conn: Conn| async move {
+ let t = Duration::from_secs(selfc.config.lookup_connection_lifespan);
+ timeout(t, selfc.handle_inbound(conn)).await??;
+ Ok(())
+ };
+
+ self.listener.start(ex, endpoint.clone(), callback).await?;
+ Ok(())
+ }
+
+ /// Handles inbound connection
+ async fn handle_inbound(self: &Arc<Self>, conn: Conn) -> Result<()> {
+ let io_codec = IOCodec::new(conn);
+ loop {
+ let msg: NetMsg = io_codec.read().await?;
+ trace!("Receive msg {:?}", msg.header.command);
+
+ if let NetMsgCmd::Shutdown = msg.header.command {
+ return Ok(());
+ }
+
+ match &msg.header.command {
+ NetMsgCmd::Ping => {
+ let (ping_msg, _) = decode::<PingMsg>(&msg.payload)?;
+ if !version_match(&self.config.version.req, &ping_msg.version) {
+ return Err(Error::IncompatibleVersion("system: {}".into()));
+ }
+ self.send_pong_msg(ping_msg.nonce, &io_codec).await?;
+ }
+ NetMsgCmd::FindPeer => {
+ let (findpeer_msg, _) = decode::<FindPeerMsg>(&msg.payload)?;
+ let peer_id = findpeer_msg.0;
+ self.send_peers_msg(&peer_id, &io_codec).await?;
+ }
+ NetMsgCmd::Peer => {
+ let (peer, _) = decode::<PeerMsg>(&msg.payload)?;
+ let result = self.table.lock().await.add_entry(peer.clone().into());
+ trace!("Add entry result: {:?}", result);
+ }
+ c => return Err(Error::InvalidMsg(format!("Unexpected msg: {:?}", c))),
+ }
+ }
+ }
+
+ /// Sends a Ping msg and wait to receive the Pong message.
+ async fn send_ping_msg(&self, io_codec: &IOCodec) -> Result<()> {
+ trace!("Send Pong msg");
+
+ let mut nonce: [u8; 32] = [0; 32];
+ RngCore::fill_bytes(&mut OsRng, &mut nonce);
+
+ let ping_msg = PingMsg {
+ version: self.config.version.v.clone(),
+ nonce,
+ };
+ io_codec.write(NetMsgCmd::Ping, &ping_msg).await?;
+
+ let t = Duration::from_secs(self.config.lookup_response_timeout);
+ let recv_msg: NetMsg = io_codec.read_timeout(t).await?;
+
+ let payload = get_msg_payload!(Pong, recv_msg);
+ let (pong_msg, _) = decode::<PongMsg>(&payload)?;
+
+ if ping_msg.nonce != pong_msg.0 {
+ return Err(Error::InvalidPongMsg);
+ }
+
+ Ok(())
+ }
+
+ /// Sends a Pong msg
+ async fn send_pong_msg(&self, nonce: [u8; 32], io_codec: &IOCodec) -> Result<()> {
+ trace!("Send Pong msg");
+ io_codec.write(NetMsgCmd::Pong, &PongMsg(nonce)).await?;
+ Ok(())
+ }
+
+ /// Sends a FindPeer msg and wait to receivet the Peers msg.
+ async fn send_findpeer_msg(&self, io_codec: &IOCodec, peer_id: &PeerID) -> Result<PeersMsg> {
+ trace!("Send FindPeer msg");
+ io_codec
+ .write(NetMsgCmd::FindPeer, &FindPeerMsg(peer_id.clone()))
+ .await?;
+
+ let t = Duration::from_secs(self.config.lookup_response_timeout);
+ let recv_msg: NetMsg = io_codec.read_timeout(t).await?;
+
+ let payload = get_msg_payload!(Peers, recv_msg);
+ let (peers, _) = decode(&payload)?;
+
+ Ok(peers)
+ }
+
+ /// Sends a Peers msg.
+ async fn send_peers_msg(&self, peer_id: &PeerID, io_codec: &IOCodec) -> Result<()> {
+ trace!("Send Peers msg");
+ let table = self.table.lock().await;
+ let entries = table.closest_entries(&peer_id.0, MAX_PEERS_IN_PEERSMSG);
+ let peers: Vec<PeerMsg> = entries.into_iter().map(|e| e.into()).collect();
+ drop(table);
+ io_codec.write(NetMsgCmd::Peers, &PeersMsg(peers)).await?;
+ Ok(())
+ }
+
+ /// Sends a Peer msg.
+ async fn send_peer_msg(&self, io_codec: &IOCodec, endpoint: Endpoint) -> Result<()> {
+ trace!("Send Peer msg");
+ let peer_msg = PeerMsg {
+ addr: endpoint.addr()?.clone(),
+ port: *endpoint.port()?,
+ discovery_port: self.config.discovery_port,
+ peer_id: self.id.clone(),
+ };
+ io_codec.write(NetMsgCmd::Peer, &peer_msg).await?;
+ Ok(())
+ }
+
+ /// Sends a Shutdown msg.
+ async fn send_shutdown_msg(&self, io_codec: &IOCodec) -> Result<()> {
+ trace!("Send Shutdown msg");
+ io_codec.write(NetMsgCmd::Shutdown, &ShutdownMsg(0)).await?;
+ Ok(())
+ }
+}
diff --git a/p2p/src/discovery/mod.rs b/p2p/src/discovery/mod.rs
new file mode 100644
index 0000000..94b350b
--- /dev/null
+++ b/p2p/src/discovery/mod.rs
@@ -0,0 +1,262 @@
+mod lookup;
+mod refresh;
+
+use std::sync::Arc;
+
+use log::{error, info};
+use rand::{rngs::OsRng, seq::SliceRandom};
+use smol::lock::Mutex;
+
+use karyons_core::{
+ async_utils::{Backoff, TaskGroup, TaskResult},
+ Executor,
+};
+
+use karyons_net::{Conn, Endpoint};
+
+use crate::{
+ config::Config,
+ monitor::Monitor,
+ net::ConnQueue,
+ net::{ConnDirection, ConnectionSlots, Connector, Listener},
+ routing_table::{
+ Entry, EntryStatusFlag, RoutingTable, CONNECTED_ENTRY, DISCONNECTED_ENTRY, PENDING_ENTRY,
+ UNREACHABLE_ENTRY, UNSTABLE_ENTRY,
+ },
+ Error, PeerID, Result,
+};
+
+use lookup::LookupService;
+use refresh::RefreshService;
+
+pub type ArcDiscovery = Arc<Discovery>;
+
+pub struct Discovery {
+ /// Routing table
+ table: Arc<Mutex<RoutingTable>>,
+
+ /// Lookup Service
+ lookup_service: Arc<LookupService>,
+
+ /// Refresh Service
+ refresh_service: Arc<RefreshService>,
+
+ /// Connector
+ connector: Arc<Connector>,
+ /// Listener
+ listener: Arc<Listener>,
+
+ /// Connection queue
+ conn_queue: Arc<ConnQueue>,
+
+ /// Inbound slots.
+ pub(crate) inbound_slots: Arc<ConnectionSlots>,
+ /// Outbound slots.
+ pub(crate) outbound_slots: Arc<ConnectionSlots>,
+
+ /// Managing spawned tasks.
+ task_group: TaskGroup,
+
+ /// Holds the configuration for the P2P network.
+ config: Arc<Config>,
+}
+
+impl Discovery {
+ /// Creates a new Discovery
+ pub fn new(
+ peer_id: &PeerID,
+ conn_queue: Arc<ConnQueue>,
+ config: Arc<Config>,
+ monitor: Arc<Monitor>,
+ ) -> ArcDiscovery {
+ let inbound_slots = Arc::new(ConnectionSlots::new(config.inbound_slots));
+ let outbound_slots = Arc::new(ConnectionSlots::new(config.outbound_slots));
+
+ let table_key = peer_id.0;
+ let table = Arc::new(Mutex::new(RoutingTable::new(table_key)));
+
+ let refresh_service = RefreshService::new(config.clone(), table.clone(), monitor.clone());
+ let lookup_service =
+ LookupService::new(peer_id, table.clone(), config.clone(), monitor.clone());
+
+ let connector = Connector::new(
+ config.max_connect_retries,
+ outbound_slots.clone(),
+ monitor.clone(),
+ );
+ let listener = Listener::new(inbound_slots.clone(), monitor.clone());
+
+ Arc::new(Self {
+ refresh_service: Arc::new(refresh_service),
+ lookup_service: Arc::new(lookup_service),
+ conn_queue,
+ table,
+ inbound_slots,
+ outbound_slots,
+ connector,
+ listener,
+ task_group: TaskGroup::new(),
+ config,
+ })
+ }
+
+ /// Start the Discovery
+ pub async fn start(self: &Arc<Self>, ex: Executor<'_>) -> Result<()> {
+ // Check if the listen_endpoint is provided, and if so, start a listener.
+ if let Some(endpoint) = &self.config.listen_endpoint {
+ // Return an error if the discovery port is set to 0.
+ if self.config.discovery_port == 0 {
+ return Err(Error::Config(
+ "Please add a valid discovery port".to_string(),
+ ));
+ }
+
+ let resolved_endpoint = self.start_listener(endpoint, ex.clone()).await?;
+
+ if endpoint.addr()? != resolved_endpoint.addr()? {
+ info!("Resolved listen endpoint: {resolved_endpoint}");
+ self.lookup_service
+ .set_listen_endpoint(&resolved_endpoint)
+ .await;
+ self.refresh_service
+ .set_listen_endpoint(&resolved_endpoint)
+ .await;
+ }
+ }
+
+ // Start the lookup service
+ self.lookup_service.start(ex.clone()).await?;
+ // Start the refresh service
+ self.refresh_service.start(ex.clone()).await?;
+
+ // Attempt to manually connect to peer endpoints provided in the Config.
+ for endpoint in self.config.peer_endpoints.iter() {
+ let _ = self.connect(endpoint, None, ex.clone()).await;
+ }
+
+ // Start connect loop
+ let selfc = self.clone();
+ self.task_group
+ .spawn(ex.clone(), selfc.connect_loop(ex), |res| async move {
+ if let TaskResult::Completed(Err(err)) = res {
+ error!("Connect loop stopped: {err}");
+ }
+ });
+
+ Ok(())
+ }
+
+ /// Shuts down the discovery
+ pub async fn shutdown(&self) {
+ self.task_group.cancel().await;
+ self.connector.shutdown().await;
+ self.listener.shutdown().await;
+
+ self.refresh_service.shutdown().await;
+ self.lookup_service.shutdown().await;
+ }
+
+ /// Start a listener and on success, return the resolved endpoint.
+ async fn start_listener(
+ self: &Arc<Self>,
+ endpoint: &Endpoint,
+ ex: Executor<'_>,
+ ) -> Result<Endpoint> {
+ let selfc = self.clone();
+ let callback = |conn: Conn| async move {
+ selfc.conn_queue.handle(conn, ConnDirection::Inbound).await;
+ Ok(())
+ };
+
+ let resolved_endpoint = self.listener.start(ex, endpoint.clone(), callback).await?;
+ Ok(resolved_endpoint)
+ }
+
+ /// This method will attempt to connect to a peer in the routing table.
+ /// If the routing table is empty, it will start the seeding process for
+ /// finding new peers.
+ ///
+ /// This will perform a backoff to prevent getting stuck in the loop
+ /// if the seeding process couldn't find any peers.
+ async fn connect_loop(self: Arc<Self>, ex: Executor<'_>) -> Result<()> {
+ let backoff = Backoff::new(500, self.config.seeding_interval * 1000);
+ loop {
+ let random_entry = self.random_entry(PENDING_ENTRY).await;
+ match random_entry {
+ Some(entry) => {
+ backoff.reset();
+ let endpoint = Endpoint::Tcp(entry.addr, entry.port);
+ self.connect(&endpoint, Some(entry.key.into()), ex.clone())
+ .await;
+ }
+ None => {
+ backoff.sleep().await;
+ self.start_seeding().await;
+ }
+ }
+ }
+ }
+
+ /// Connect to the given endpoint using the connector
+ async fn connect(self: &Arc<Self>, endpoint: &Endpoint, pid: Option<PeerID>, ex: Executor<'_>) {
+ let selfc = self.clone();
+ let pid_cloned = pid.clone();
+ let cback = |conn: Conn| async move {
+ selfc.conn_queue.handle(conn, ConnDirection::Outbound).await;
+ if let Some(pid) = pid_cloned {
+ selfc.update_entry(&pid, DISCONNECTED_ENTRY).await;
+ }
+ Ok(())
+ };
+
+ let res = self.connector.connect_with_cback(ex, endpoint, cback).await;
+
+ if let Some(pid) = &pid {
+ match res {
+ Ok(_) => {
+ self.update_entry(pid, CONNECTED_ENTRY).await;
+ }
+ Err(_) => {
+ self.update_entry(pid, UNREACHABLE_ENTRY).await;
+ }
+ }
+ }
+ }
+
+ /// Starts seeding process.
+ ///
+ /// This method randomly selects a peer from the routing table and
+ /// attempts to connect to that peer for the initial lookup. If the routing
+ /// table doesn't have an available entry, it will connect to one of the
+ /// provided bootstrap endpoints in the `Config` and initiate the lookup.
+ async fn start_seeding(&self) {
+ match self.random_entry(PENDING_ENTRY | CONNECTED_ENTRY).await {
+ Some(entry) => {
+ let endpoint = Endpoint::Tcp(entry.addr, entry.discovery_port);
+ if let Err(err) = self.lookup_service.start_lookup(&endpoint).await {
+ self.update_entry(&entry.key.into(), UNSTABLE_ENTRY).await;
+ error!("Failed to do lookup: {endpoint}: {err}");
+ }
+ }
+ None => {
+ let peers = &self.config.bootstrap_peers;
+ for endpoint in peers.choose_multiple(&mut OsRng, peers.len()) {
+ if let Err(err) = self.lookup_service.start_lookup(endpoint).await {
+ error!("Failed to do lookup: {endpoint}: {err}");
+ }
+ }
+ }
+ }
+ }
+
+ /// Returns a random entry from routing table.
+ async fn random_entry(&self, entry_flag: EntryStatusFlag) -> Option<Entry> {
+ self.table.lock().await.random_entry(entry_flag).cloned()
+ }
+
+ /// Update the entry status
+ async fn update_entry(&self, pid: &PeerID, entry_flag: EntryStatusFlag) {
+ let table = &mut self.table.lock().await;
+ table.update_entry(&pid.0, entry_flag);
+ }
+}
diff --git a/p2p/src/discovery/refresh.rs b/p2p/src/discovery/refresh.rs
new file mode 100644
index 0000000..7582c84
--- /dev/null
+++ b/p2p/src/discovery/refresh.rs
@@ -0,0 +1,289 @@
+use std::{sync::Arc, time::Duration};
+
+use bincode::{Decode, Encode};
+use log::{error, info, trace};
+use rand::{rngs::OsRng, RngCore};
+use smol::{
+ lock::{Mutex, RwLock},
+ stream::StreamExt,
+ Timer,
+};
+
+use karyons_core::{
+ async_utils::{timeout, Backoff, TaskGroup, TaskResult},
+ utils::{decode, encode},
+ Executor,
+};
+
+use karyons_net::{dial_udp, listen_udp, Addr, Connection, Endpoint, NetError, Port, UdpConn};
+
+/// Maximum failures for an entry before removing it from the routing table.
+pub const MAX_FAILURES: u32 = 3;
+
+/// Ping message size
+const PINGMSG_SIZE: usize = 32;
+
+use crate::{
+ monitor::{ConnEvent, DiscoveryEvent, Monitor},
+ routing_table::{BucketEntry, Entry, RoutingTable, PENDING_ENTRY, UNREACHABLE_ENTRY},
+ Config, Error, Result,
+};
+
+#[derive(Decode, Encode, Debug, Clone)]
+pub struct PingMsg(pub [u8; 32]);
+
+#[derive(Decode, Encode, Debug)]
+pub struct PongMsg(pub [u8; 32]);
+
+pub struct RefreshService {
+ /// Routing table
+ table: Arc<Mutex<RoutingTable>>,
+
+ /// Resolved listen endpoint
+ listen_endpoint: Option<RwLock<Endpoint>>,
+
+ /// Managing spawned tasks.
+ task_group: TaskGroup,
+
+ /// Holds the configuration for the P2P network.
+ config: Arc<Config>,
+
+ /// Responsible for network and system monitoring.
+ monitor: Arc<Monitor>,
+}
+
+impl RefreshService {
+ /// Creates a new refresh service
+ pub fn new(
+ config: Arc<Config>,
+ table: Arc<Mutex<RoutingTable>>,
+ monitor: Arc<Monitor>,
+ ) -> Self {
+ let listen_endpoint = config
+ .listen_endpoint
+ .as_ref()
+ .map(|endpoint| RwLock::new(endpoint.clone()));
+
+ Self {
+ table,
+ listen_endpoint,
+ task_group: TaskGroup::new(),
+ config,
+ monitor,
+ }
+ }
+
+ /// Start the refresh service
+ pub async fn start(self: &Arc<Self>, ex: Executor<'_>) -> Result<()> {
+ if let Some(endpoint) = &self.listen_endpoint {
+ let endpoint = endpoint.read().await;
+ let addr = endpoint.addr()?;
+ let port = self.config.discovery_port;
+
+ let selfc = self.clone();
+ self.task_group.spawn(
+ ex.clone(),
+ selfc.listen_loop(addr.clone(), port),
+ |res| async move {
+ if let TaskResult::Completed(Err(err)) = res {
+ error!("Listen loop stopped: {err}");
+ }
+ },
+ );
+ }
+
+ let selfc = self.clone();
+ self.task_group.spawn(
+ ex.clone(),
+ selfc.refresh_loop(ex.clone()),
+ |res| async move {
+ if let TaskResult::Completed(Err(err)) = res {
+ error!("Refresh loop stopped: {err}");
+ }
+ },
+ );
+
+ Ok(())
+ }
+
+ /// Set the resolved listen endpoint.
+ pub async fn set_listen_endpoint(&self, resolved_endpoint: &Endpoint) {
+ if let Some(endpoint) = &self.listen_endpoint {
+ *endpoint.write().await = resolved_endpoint.clone();
+ }
+ }
+
+ /// Shuts down the refresh service
+ pub async fn shutdown(&self) {
+ self.task_group.cancel().await;
+ }
+
+ /// Initiates periodic refreshing of the routing table. This function will
+ /// select 8 random entries from each bucket in the routing table and start
+ /// sending Ping messages to the entries.
+ async fn refresh_loop(self: Arc<Self>, ex: Executor<'_>) -> Result<()> {
+ let mut timer = Timer::interval(Duration::from_secs(self.config.refresh_interval));
+ loop {
+ timer.next().await;
+ trace!("Start refreshing the routing table...");
+
+ self.monitor
+ .notify(&DiscoveryEvent::RefreshStarted.into())
+ .await;
+
+ let table = self.table.lock().await;
+ let mut entries: Vec<BucketEntry> = vec![];
+ for bucket in table.iter() {
+ for entry in bucket.random_iter(8) {
+ entries.push(entry.clone())
+ }
+ }
+ drop(table);
+
+ self.clone().do_refresh(&entries, ex.clone()).await;
+ }
+ }
+
+ /// Iterates over the entries and spawns a new task for each entry to
+ /// initiate a connection attempt to that entry.
+ async fn do_refresh(self: Arc<Self>, entries: &[BucketEntry], ex: Executor<'_>) {
+ for chunk in entries.chunks(16) {
+ let mut tasks = Vec::new();
+ for bucket_entry in chunk {
+ if bucket_entry.is_connected() {
+ continue;
+ }
+
+ if bucket_entry.failures >= MAX_FAILURES {
+ self.table
+ .lock()
+ .await
+ .remove_entry(&bucket_entry.entry.key);
+ return;
+ }
+
+ tasks.push(ex.spawn(self.clone().refresh_entry(bucket_entry.clone())))
+ }
+
+ for task in tasks {
+ task.await;
+ }
+ }
+ }
+
+ /// Initiates refresh for a specific entry within the routing table. It
+ /// updates the routing table according to the result.
+ async fn refresh_entry(self: Arc<Self>, bucket_entry: BucketEntry) {
+ let key = &bucket_entry.entry.key;
+ match self.connect(&bucket_entry.entry).await {
+ Ok(_) => {
+ self.table.lock().await.update_entry(key, PENDING_ENTRY);
+ }
+ Err(err) => {
+ trace!("Failed to refresh entry {:?}: {err}", key);
+ let table = &mut self.table.lock().await;
+ if bucket_entry.failures >= MAX_FAILURES {
+ table.remove_entry(key);
+ return;
+ }
+ table.update_entry(key, UNREACHABLE_ENTRY);
+ }
+ }
+ }
+
+ /// Initiates a UDP connection with the entry and attempts to send a Ping
+ /// message. If it fails, it retries according to the allowed retries
+ /// specified in the Config, with backoff between each retry.
+ async fn connect(&self, entry: &Entry) -> Result<()> {
+ let mut retry = 0;
+ let conn = dial_udp(&entry.addr, &entry.discovery_port).await?;
+ let backoff = Backoff::new(100, 5000);
+ while retry < self.config.refresh_connect_retries {
+ match self.send_ping_msg(&conn).await {
+ Ok(()) => return Ok(()),
+ Err(Error::KaryonsNet(NetError::Timeout)) => {
+ retry += 1;
+ backoff.sleep().await;
+ }
+ Err(err) => {
+ return Err(err);
+ }
+ }
+ }
+
+ Err(NetError::Timeout.into())
+ }
+
+ /// Set up a UDP listener and start listening for Ping messages from other
+ /// peers.
+ async fn listen_loop(self: Arc<Self>, addr: Addr, port: Port) -> Result<()> {
+ let endpoint = Endpoint::Udp(addr.clone(), port);
+ let conn = match listen_udp(&addr, &port).await {
+ Ok(c) => {
+ self.monitor
+ .notify(&ConnEvent::Listening(endpoint.clone()).into())
+ .await;
+ c
+ }
+ Err(err) => {
+ self.monitor
+ .notify(&ConnEvent::ListenFailed(endpoint.clone()).into())
+ .await;
+ return Err(err.into());
+ }
+ };
+ info!("Start listening on {endpoint}");
+
+ loop {
+ let res = self.listen_to_ping_msg(&conn).await;
+ if let Err(err) = res {
+ trace!("Failed to handle ping msg {err}");
+ self.monitor.notify(&ConnEvent::AcceptFailed.into()).await;
+ }
+ }
+ }
+
+ /// Listen to receive a Ping message and respond with a Pong message.
+ async fn listen_to_ping_msg(&self, conn: &UdpConn) -> Result<()> {
+ let mut buf = [0; PINGMSG_SIZE];
+ let (_, endpoint) = conn.recv_from(&mut buf).await?;
+
+ self.monitor
+ .notify(&ConnEvent::Accepted(endpoint.clone()).into())
+ .await;
+
+ let (ping_msg, _) = decode::<PingMsg>(&buf)?;
+
+ let pong_msg = PongMsg(ping_msg.0);
+ let buffer = encode(&pong_msg)?;
+
+ conn.send_to(&buffer, &endpoint).await?;
+
+ self.monitor
+ .notify(&ConnEvent::Disconnected(endpoint.clone()).into())
+ .await;
+ Ok(())
+ }
+
+ /// Sends a Ping msg and wait to receive the Pong message.
+ async fn send_ping_msg(&self, conn: &UdpConn) -> Result<()> {
+ let mut nonce: [u8; 32] = [0; 32];
+ RngCore::fill_bytes(&mut OsRng, &mut nonce);
+
+ let ping_msg = PingMsg(nonce);
+ let buffer = encode(&ping_msg)?;
+ conn.send(&buffer).await?;
+
+ let buf = &mut [0; PINGMSG_SIZE];
+ let t = Duration::from_secs(self.config.refresh_response_timeout);
+ timeout(t, conn.recv(buf)).await??;
+
+ let (pong_msg, _) = decode::<PongMsg>(buf)?;
+
+ if ping_msg.0 != pong_msg.0 {
+ return Err(Error::InvalidPongMsg);
+ }
+
+ Ok(())
+ }
+}
generated by cgit v1.2.3 (git 2.39.1) at 2024-09-20 01:45:56 +0000