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Radicle Heartwood Protocol & Stack
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protocol: peer connections
Fintan Halpenny committed 10 months ago
commit a2c0d12fa32b1e3eda9f8078b84e979953b10226
parent 1a43ebeff41cea3750472e69bc953b27c257c408
7 files changed +1215 -0
added crates/radicle-protocol/src/connections.rs
@@ -0,0 +1,399 @@
+ 
// TODO(finto): command should be something else, perhaps `input`?
+ 
pub mod command;
+ 
pub use command::{Connect, Disconnect};
+
+ 
pub mod commands;
+ 
pub mod effects;
+ 
pub mod events;
+
+ 
use radicle::node::config::RateLimits;
+ 
use session::{HasAttempts as _, Session, Sessions};
+ 
mod session;
+
+ 
use std::collections::HashSet;
+ 
use std::net::IpAddr;
+
+ 
use localtime::{LocalDuration, LocalTime};
+ 
use radicle::node::address;
+ 
use radicle::node::{Address, HostName, Link, NodeId, Severity};
+
+ 
use crate::service::limiter::RateLimiter;
+ 
use crate::service::DisconnectReason;
+
+ 
/// Minimum amount of time to wait before reconnecting to a peer.
+ 
pub const MIN_RECONNECTION_DELTA: LocalDuration = LocalDuration::from_secs(3);
+ 
/// Maximum amount of time to wait before reconnecting to a peer.
+ 
pub const MAX_RECONNECTION_DELTA: LocalDuration = LocalDuration::from_mins(60);
+
+ 
pub struct Connections {
+ 
    /// The state of the connection lifecycle for each node in the network.
+ 
    sessions: Sessions,
+ 
    /// Keep track of which node connections are meant to be persistent.
+ 
    persistent: HashSet<NodeId>,
+ 
    /// Keep track of banned IP addresses.
+ 
    banned: HashSet<IpAddr>,
+ 
    /// Rate limiter of IP hosts.
+ 
    limiter: RateLimiter,
+ 
    /// Configuration for managing connections.
+ 
    config: Config,
+ 
}
+
+ 
pub struct Config {
+ 
    /// Duration for a connection to be considered idle.
+ 
    idle: LocalDuration,
+ 
    /// Allowed number of inbound connections
+ 
    inbound_limit: usize,
+ 
    limits: RateLimits,
+ 
    reconnection_delay: ReconnectionDelay,
+ 
}
+
+ 
#[derive(Clone, Copy, Debug, PartialEq, Eq)]
+ 
pub struct ReconnectionDelay {
+ 
    /// The minimum amount of time to wait before attempting a re-connection.
+ 
    pub min_delta: LocalDuration,
+ 
    /// The maximum amount of time to wait before attempting a re-connection.
+ 
    pub max_delta: LocalDuration,
+ 
}
+
+ 
impl Default for ReconnectionDelay {
+ 
    fn default() -> Self {
+ 
        Self {
+ 
            min_delta: MIN_RECONNECTION_DELTA,
+ 
            max_delta: MAX_RECONNECTION_DELTA,
+ 
        }
+ 
    }
+ 
}
+
+ 
pub enum CommandEvent {
+ 
    MissingSession { node: NodeId },
+ 
    Attempted(Session<session::Attempted>),
+ 
    Connected(Session<session::Connected>),
+ 
    Disconnected(Session<session::Disconnected>),
+ 
}
+
+ 
impl Connections {
+ 
    pub fn handle_command(&mut self, command: commands::Command) -> CommandEvent {
+ 
        match command {
+ 
            commands::Command::Attempt(attempt) => self.attempted(attempt),
+ 
            commands::Command::Connect(connect) => self.connected(connect),
+ 
            commands::Command::Disconnect(disconnect) => self.disconnected(disconnect),
+ 
        }
+ 
    }
+
+ 
    fn attempted(&mut self, commands::Attempt { node }: commands::Attempt) -> CommandEvent {
+ 
        self.sessions
+ 
            .session_to_attempted(&node)
+ 
            .map(CommandEvent::Attempted)
+ 
            .unwrap_or(CommandEvent::MissingSession { node })
+ 
    }
+
+ 
    fn connected(
+ 
        &mut self,
+ 
        commands::Connect {
+ 
            node,
+ 
            now,
+ 
            link,
+ 
            persistent,
+ 
        }: commands::Connect,
+ 
    ) -> CommandEvent {
+ 
        self.sessions
+ 
            .session_to_connected(&node, now, link, persistent)
+ 
            .map(CommandEvent::Connected)
+ 
            .unwrap_or(CommandEvent::MissingSession { node })
+ 
    }
+
+ 
    fn disconnected(
+ 
        &mut self,
+ 
        commands::Disconnect {
+ 
            node,
+ 
            since,
+ 
            retry_at,
+ 
        }: commands::Disconnect,
+ 
    ) -> CommandEvent {
+ 
        self.sessions
+ 
            .session_to_disconnected(&node, since, retry_at)
+ 
            .map(CommandEvent::Disconnected)
+ 
            .unwrap_or(CommandEvent::MissingSession { node })
+ 
    }
+ 
}
+
+ 
impl Connections {
+ 
    pub fn sessions(&self) -> &Sessions {
+ 
        &self.sessions
+ 
    }
+
+ 
    pub fn accept(&mut self, ip: IpAddr, now: LocalTime) -> AcceptResult {
+ 
        let mut result = AcceptResult::default();
+ 
        // Always accept localhost connections, even if we already reached
+ 
        // our inbound connection limit.
+ 
        if ip.is_loopback() || ip.is_unspecified() {
+ 
            result.local_host(ip);
+ 
            return result;
+ 
        }
+
+ 
        if self.has_reached_inbound_limit() {
+ 
            result.inbound_limit_exceeded(ip, self.sessions.connected_inbound());
+ 
            return result;
+ 
        }
+
+ 
        if self.is_ip_banned(&ip) {
+ 
            result.ip_banned(ip);
+ 
            return result;
+ 
        }
+
+ 
        if self.has_reached_ip_limit(&ip, now) {
+ 
            result.host_limited(ip);
+ 
            return result;
+ 
        }
+
+ 
        result.accepted(ip);
+ 
        result
+ 
    }
+
+ 
    pub fn connect(&self, connect: Connect) -> ConnectResult {
+ 
        let mut result = ConnectResult::default();
+ 
        match connect {
+ 
            Connect::Inbound(command::Inbound {
+ 
                node,
+ 
                clock,
+ 
                persistent,
+ 
            }) => match self.sessions.get_connected(&node) {
+ 
                Some(session) => result.already_connected(session.clone(), Link::Inbound),
+ 
                None => {
+ 
                    result.connect(node, clock, Link::Inbound, persistent);
+ 
                    result.send_initial_messages(node, Link::Inbound);
+ 
                }
+ 
            },
+ 
            Connect::Outbound(command::Outbound {
+ 
                node,
+ 
                addr,
+ 
                persistent,
+ 
                clock,
+ 
            }) => match self.sessions.get_connected(&node) {
+ 
                Some(session) => {
+ 
                    result.already_connected(session.clone(), Link::Outbound);
+ 
                    result.send_initial_messages(node, *session.link());
+ 
                }
+ 
                None => {
+ 
                    if let HostName::Ip(ip) = addr.host {
+ 
                        if !address::is_local(&ip) {
+ 
                            result.record_ip(node, ip, clock);
+ 
                        }
+ 
                    }
+ 
                    result.connect(node, clock, Link::Outbound, persistent);
+ 
                    result.send_initial_messages(node, Link::Outbound);
+ 
                }
+ 
            },
+ 
        }
+ 
        result
+ 
    }
+
+ 
    pub fn disconnect(&self, disconnect: Disconnect) -> DisconnectResult {
+ 
        let mut result = DisconnectResult::default();
+ 
        let Disconnect {
+ 
            node,
+ 
            link,
+ 
            reason,
+ 
            since,
+ 
        } = disconnect;
+ 
        let is_persistent = self.is_persistent(&node);
+ 
        let Some(session) = self.sessions.get_session(&node) else {
+ 
            result.already_disconnected(node);
+ 
            return result;
+ 
        };
+ 
        if *session.link() != link {
+ 
            result.link_conflict(node, *session.link(), link);
+ 
            return result;
+ 
        }
+
+ 
        if is_persistent {
+ 
            let delay = self.reconnection_delay(session.attempts().as_u32());
+ 
            let retry_at = since + delay;
+ 
            result.retry_connection(node, since, retry_at);
+ 
            result.disconnect(node, since, Some(retry_at));
+ 
        } else {
+ 
            let severity = self.reason_severity(reason, since);
+ 
            result.record_severity(node, session.address().clone(), severity);
+ 
            result.disconnect(node, since, None);
+ 
            if link.is_outbound() {
+ 
                result.maintain_connnections();
+ 
            }
+ 
        }
+ 
        result
+ 
    }
+
+ 
    fn reason_severity(&self, reason: DisconnectReason, now: LocalTime) -> Severity {
+ 
        match reason {
+ 
            DisconnectReason::Dial(_)
+ 
            | DisconnectReason::Fetch(_)
+ 
            | DisconnectReason::Connection(_) => {
+ 
                if self.is_online(now) {
+ 
                    // If we're "online", there's something wrong with this
+ 
                    // peer connection specifically.
+ 
                    Severity::Medium
+ 
                } else {
+ 
                    Severity::Low
+ 
                }
+ 
            }
+ 
            DisconnectReason::Session(e) => e.severity(),
+ 
            DisconnectReason::Command
+ 
            | DisconnectReason::Conflict
+ 
            | DisconnectReason::SelfConnection => Severity::Low,
+ 
        }
+ 
    }
+
+ 
    /// Try to guess whether we're online or not.
+ 
    fn is_online(&self, now: LocalTime) -> bool {
+ 
        self.sessions
+ 
            .connected()
+ 
            .filter(|(_, s)| s.address().is_routable() && *s.last_active() >= now - self.idle())
+ 
            .count()
+ 
            > 0
+ 
    }
+
+ 
    fn idle(&self) -> LocalDuration {
+ 
        self.config.idle
+ 
    }
+
+ 
    fn is_persistent(&self, node: &NodeId) -> bool {
+ 
        self.persistent.contains(node)
+ 
    }
+
+ 
    fn is_ip_banned(&self, ip: &IpAddr) -> bool {
+ 
        self.banned.contains(ip)
+ 
    }
+
+ 
    // TODO: limit is harshing my buzz by taking &mut self here
+ 
    fn has_reached_ip_limit(&mut self, ip: &IpAddr, now: LocalTime) -> bool {
+ 
        let addr = HostName::from(*ip);
+ 
        self.limiter
+ 
            .limit(addr, None, &self.config.limits.inbound, now)
+ 
    }
+
+ 
    fn has_reached_inbound_limit(&self) -> bool {
+ 
        self.sessions.connected_inbound() >= self.config.inbound_limit
+ 
    }
+
+ 
    fn reconnection_delay(&self, attempts: u32) -> LocalDuration {
+ 
        LocalDuration::from_secs(2u64.pow(attempts)).clamp(
+ 
            self.config.reconnection_delay.min_delta,
+ 
            self.config.reconnection_delay.max_delta,
+ 
        )
+ 
    }
+ 
}
+
+ 
#[derive(Debug, Default)]
+ 
pub struct AcceptResult {
+ 
    pub effects: Vec<effects::Accept>,
+ 
    pub events: Vec<events::Accept>,
+ 
}
+
+ 
impl AcceptResult {
+ 
    fn local_host(&mut self, ip: IpAddr) {
+ 
        self.effects.push(effects::Accept::LocalHost { ip });
+ 
    }
+
+ 
    fn inbound_limit_exceeded(&mut self, ip: IpAddr, connected_inbound: usize) {
+ 
        self.events.push(events::Accept::LimitExceeded {
+ 
            ip,
+ 
            current_inbound: connected_inbound,
+ 
        });
+ 
    }
+
+ 
    fn ip_banned(&mut self, ip: IpAddr) {
+ 
        self.events.push(events::Accept::IpBanned { ip })
+ 
    }
+
+ 
    fn host_limited(&mut self, ip: IpAddr) {
+ 
        self.events.push(events::Accept::HostLimited { ip })
+ 
    }
+
+ 
    fn accepted(&mut self, ip: IpAddr) {
+ 
        self.effects.push(effects::Accept::Accepted { ip })
+ 
    }
+ 
}
+
+ 
#[derive(Clone, Debug, Default, PartialEq, Eq)]
+ 
pub struct ConnectResult {
+ 
    pub events: Vec<events::Connect>,
+ 
    pub effects: Vec<effects::Connect>,
+ 
    pub commands: Vec<commands::Connect>,
+ 
}
+
+ 
impl ConnectResult {
+ 
    fn already_connected(&mut self, session: Session<session::Connected>, attempted_link: Link) {
+ 
        self.events.push(events::Connect::AlreadyConnected {
+ 
            session,
+ 
            attempted_link,
+ 
        });
+ 
    }
+
+ 
    fn send_initial_messages(&mut self, node: NodeId, link: Link) {
+ 
        self.effects
+ 
            .push(effects::Connect::SendInitialMessages { node, link });
+ 
    }
+
+ 
    fn record_ip(&mut self, node: NodeId, ip: IpAddr, clock: LocalTime) {
+ 
        self.effects
+ 
            .push(effects::Connect::RecordIp { node, ip, clock });
+ 
    }
+
+ 
    fn connect(&mut self, node: NodeId, clock: LocalTime, link: Link, persistent: bool) {
+ 
        self.commands.push(commands::Connect {
+ 
            node,
+ 
            now: clock,
+ 
            link,
+ 
            persistent,
+ 
        });
+ 
    }
+ 
}
+
+ 
#[derive(Clone, Debug, Default, PartialEq, Eq)]
+ 
pub struct DisconnectResult {
+ 
    pub events: Vec<events::Disconnect>,
+ 
    pub effects: Vec<effects::Disconnect>,
+ 
    pub commands: Vec<commands::Disconnect>,
+ 
}
+
+ 
impl DisconnectResult {
+ 
    fn already_disconnected(&mut self, node: NodeId) {
+ 
        self.events
+ 
            .push(events::Disconnect::AlreadyDisconnected { node });
+ 
    }
+
+ 
    fn link_conflict(&mut self, node: NodeId, found: Link, expected: Link) {
+ 
        self.events.push(events::Disconnect::LinkConflict {
+ 
            node,
+ 
            found,
+ 
            expected,
+ 
        });
+ 
    }
+
+ 
    fn retry_connection(&mut self, node: NodeId, since: LocalTime, retry_at: LocalTime) {
+ 
        self.effects.push(effects::Disconnect::RetryConnection {
+ 
            node,
+ 
            since,
+ 
            retry_at,
+ 
        });
+ 
    }
+
+ 
    fn maintain_connnections(&mut self) {
+ 
        self.effects.push(effects::Disconnect::MaintainConnections);
+ 
    }
+
+ 
    fn record_severity(&mut self, node: NodeId, address: Address, severity: Severity) {
+ 
        self.effects.push(effects::Disconnect::RecordServerity {
+ 
            node,
+ 
            address,
+ 
            severity,
+ 
        })
+ 
    }
+
+ 
    fn disconnect(&mut self, node: NodeId, since: LocalTime, retry_at: Option<LocalTime>) {
+ 
        self.commands.push(commands::Disconnect {
+ 
            node,
+ 
            since,
+ 
            retry_at,
+ 
        });
+ 
    }
+ 
}
added crates/radicle-protocol/src/connections/command.rs
@@ -0,0 +1,49 @@
+ 
use localtime::LocalTime;
+
+ 
use radicle::node::{Address, Link, NodeId};
+
+ 
use crate::service::DisconnectReason;
+
+ 
pub enum Connect {
+ 
    Inbound(Inbound),
+ 
    Outbound(Outbound),
+ 
}
+
+ 
impl Connect {
+ 
    pub fn inbound(node: NodeId, clock: LocalTime, persistent: bool) -> Self {
+ 
        Self::Inbound(Inbound {
+ 
            node,
+ 
            clock,
+ 
            persistent,
+ 
        })
+ 
    }
+
+ 
    pub fn outbound(node: NodeId, addr: Address, persistent: bool, clock: LocalTime) -> Self {
+ 
        Self::Outbound(Outbound {
+ 
            node,
+ 
            addr,
+ 
            persistent,
+ 
            clock,
+ 
        })
+ 
    }
+ 
}
+
+ 
pub struct Inbound {
+ 
    pub(super) node: NodeId,
+ 
    pub(super) clock: LocalTime,
+ 
    pub(super) persistent: bool,
+ 
}
+
+ 
pub struct Outbound {
+ 
    pub(super) node: NodeId,
+ 
    pub(super) addr: Address,
+ 
    pub(super) persistent: bool,
+ 
    pub(super) clock: LocalTime,
+ 
}
+
+ 
pub struct Disconnect {
+ 
    pub(super) node: NodeId,
+ 
    pub(super) link: Link,
+ 
    pub(super) reason: DisconnectReason,
+ 
    pub(super) since: LocalTime,
+ 
}
added crates/radicle-protocol/src/connections/commands.rs
@@ -0,0 +1,46 @@
+ 
use localtime::LocalTime;
+ 
use radicle::node::{Link, NodeId};
+
+ 
pub enum Command {
+ 
    Attempt(Attempt),
+ 
    Connect(Connect),
+ 
    Disconnect(Disconnect),
+ 
}
+
+ 
impl From<Attempt> for Command {
+ 
    fn from(v: Attempt) -> Self {
+ 
        Self::Attempt(v)
+ 
    }
+ 
}
+
+ 
impl From<Connect> for Command {
+ 
    fn from(v: Connect) -> Self {
+ 
        Self::Connect(v)
+ 
    }
+ 
}
+
+ 
impl From<Disconnect> for Command {
+ 
    fn from(v: Disconnect) -> Self {
+ 
        Self::Disconnect(v)
+ 
    }
+ 
}
+
+ 
#[derive(Clone, Copy, Debug, PartialEq, Eq)]
+ 
pub struct Attempt {
+ 
    pub node: NodeId,
+ 
}
+
+ 
#[derive(Clone, Copy, Debug, PartialEq, Eq)]
+ 
pub struct Connect {
+ 
    pub node: NodeId,
+ 
    pub now: LocalTime,
+ 
    pub link: Link,
+ 
    pub persistent: bool,
+ 
}
+
+ 
#[derive(Clone, Debug, PartialEq, Eq)]
+ 
pub struct Disconnect {
+ 
    pub node: NodeId,
+ 
    pub since: LocalTime,
+ 
    pub retry_at: Option<LocalTime>,
+ 
}
added crates/radicle-protocol/src/connections/effects.rs
@@ -0,0 +1,100 @@
+ 
//! External effects that are emitted by interacting with [`Connections`]. These
+ 
//! effects should be used by the rest of the system to perform side-effects.
+ 
//!
+ 
//! [`Connections`]: super::Connections.
+
+ 
use std::net::IpAddr;
+
+ 
use localtime::LocalTime;
+ 
use radicle::node::{Address, Link, NodeId, Severity};
+
+ 
/// All effects that can occur from interacting with [`Connections`].
+ 
///
+ 
/// [`Connections`]: super::Connections.
+ 
pub enum Effect {
+ 
    Accept(Accept),
+ 
    Connect(Connect),
+ 
    Disconnect(Disconnect),
+ 
}
+
+ 
impl From<Accept> for Effect {
+ 
    fn from(v: Accept) -> Self {
+ 
        Self::Accept(v)
+ 
    }
+ 
}
+
+ 
impl From<Connect> for Effect {
+ 
    fn from(v: Connect) -> Self {
+ 
        Self::Connect(v)
+ 
    }
+ 
}
+
+ 
impl From<Disconnect> for Effect {
+ 
    fn from(v: Disconnect) -> Self {
+ 
        Self::Disconnect(v)
+ 
    }
+ 
}
+
+ 
/// Effects that occur when checking for accepting a connection from an
+ 
/// [`IpAddr`].
+ 
#[derive(Clone, Copy, Debug, PartialEq, Eq, Hash)]
+ 
pub enum Accept {
+ 
    /// The [`IpAddr`] is likely a localhost connection.
+ 
    LocalHost { ip: IpAddr },
+ 
    /// The [`IpAddr`] should be accepted by the system, and later connected to.
+ 
    Accepted { ip: IpAddr },
+ 
}
+
+ 
impl Accept {
+ 
    /// The [`Accept::LocalHost`] should be created only if the [`IpAddr`] is
+ 
    /// either a loopback address or has an 'unspecified' address (see
+ 
    /// [`IpAddr::is_unspecified`]).
+ 
    pub fn local_host(ip: IpAddr) -> Option<Self> {
+ 
        (ip.is_loopback() || ip.is_unspecified()).then_some(Self::LocalHost { ip })
+ 
    }
+
+ 
    /// See [`Accept::Accepted`].
+ 
    pub fn accepted(ip: IpAddr) -> Self {
+ 
        Self::Accepted { ip }
+ 
    }
+ 
}
+
+ 
/// Effects that occur when connecting a node.
+ 
#[derive(Clone, Copy, Debug, PartialEq, Eq)]
+ 
pub enum Connect {
+ 
    /// The set of initial messages should be sent to the [`NodeId`].
+ 
    SendInitialMessages { node: NodeId, link: Link },
+ 
    /// The [`IpAddr`] of the [`NodeId`] should be recorded in an external
+ 
    /// database.
+ 
    RecordIp {
+ 
        node: NodeId,
+ 
        ip: IpAddr,
+ 
        clock: LocalTime,
+ 
    },
+ 
}
+
+ 
/// Effects that occur when disconnecting a node.
+ 
#[derive(Clone, Debug, PartialEq, Eq)]
+ 
pub enum Disconnect {
+ 
    /// The connection to [`NodeId`] was disconnected, but re-connection should
+ 
    /// be attempted at the given point in time.
+ 
    RetryConnection {
+ 
        /// The node that should be re-connected to.
+ 
        node: NodeId,
+ 
        /// When the node was disconnected.
+ 
        since: LocalTime,
+ 
        /// When the re-connection attempt should be made.
+ 
        retry_at: LocalTime,
+ 
    },
+ 
    /// Record the severity of the disconnect reason.
+ 
    RecordServerity {
+ 
        /// The node that was disconnected.
+ 
        node: NodeId,
+ 
        /// The address of the node that was disconnected.
+ 
        address: Address,
+ 
        /// The severity of the disconnect reason.
+ 
        severity: Severity,
+ 
    },
+ 
    /// Try to maintain all connections that are meant to be persistent.
+ 
    MaintainConnections,
+ 
}
added crates/radicle-protocol/src/connections/events.rs
@@ -0,0 +1,58 @@
+ 
use std::net::IpAddr;
+
+ 
use radicle::node::{Link, NodeId};
+
+ 
use super::session;
+ 
use super::session::Session;
+
+ 
#[derive(Clone, Debug, PartialEq, Eq)]
+ 
pub enum Event {
+ 
    Accept(Accept),
+ 
    Connect(Box<Connect>),
+ 
    Disconnect(Disconnect),
+ 
}
+
+ 
impl From<Disconnect> for Event {
+ 
    fn from(v: Disconnect) -> Self {
+ 
        Self::Disconnect(v)
+ 
    }
+ 
}
+
+ 
impl From<Connect> for Event {
+ 
    fn from(v: Connect) -> Self {
+ 
        Self::Connect(Box::new(v))
+ 
    }
+ 
}
+
+ 
impl From<Accept> for Event {
+ 
    fn from(v: Accept) -> Self {
+ 
        Self::Accept(v)
+ 
    }
+ 
}
+
+ 
#[derive(Clone, Copy, Debug, PartialEq, Eq, Hash)]
+ 
pub enum Accept {
+ 
    LimitExceeded { ip: IpAddr, current_inbound: usize },
+ 
    IpBanned { ip: IpAddr },
+ 
    HostLimited { ip: IpAddr },
+ 
}
+
+ 
#[derive(Clone, Debug, PartialEq, Eq)]
+ 
pub enum Connect {
+ 
    AlreadyConnected {
+ 
        session: Session<session::Connected>,
+ 
        attempted_link: Link,
+ 
    },
+ 
}
+
+ 
#[derive(Clone, Copy, Debug, PartialEq, Eq)]
+ 
pub enum Disconnect {
+ 
    AlreadyDisconnected {
+ 
        node: NodeId,
+ 
    },
+ 
    LinkConflict {
+ 
        node: NodeId,
+ 
        found: Link,
+ 
        expected: Link,
+ 
    },
+ 
}
added crates/radicle-protocol/src/connections/session.rs
@@ -0,0 +1,562 @@
+ 
use std::collections::{HashMap, HashSet, VecDeque};
+
+ 
use localtime::{LocalDuration, LocalTime};
+ 
use radicle::{
+ 
    node::{Address, Link, NodeId, PingState},
+ 
    prelude::RepoId,
+ 
};
+
+ 
use crate::service::message;
+
+ 
/// Time after which a connection is considered stable.
+ 
#[allow(unused)]
+ 
pub const CONNECTION_STABLE_THRESHOLD: LocalDuration = LocalDuration::from_mins(1);
+
+ 
#[derive(Clone, Debug)]
+ 
pub enum State {
+ 
    Initial(Initial),
+ 
    Attempted(Attempted),
+ 
    Connected(Connected),
+ 
    Disconnected(Disconnected),
+ 
}
+
+ 
impl From<Initial> for State {
+ 
    fn from(value: Initial) -> Self {
+ 
        Self::Initial(value)
+ 
    }
+ 
}
+
+ 
impl From<Attempted> for State {
+ 
    fn from(value: Attempted) -> Self {
+ 
        Self::Attempted(value)
+ 
    }
+ 
}
+
+ 
impl From<Connected> for State {
+ 
    fn from(value: Connected) -> Self {
+ 
        Self::Connected(value)
+ 
    }
+ 
}
+
+ 
impl From<Disconnected> for State {
+ 
    fn from(value: Disconnected) -> Self {
+ 
        Self::Disconnected(value)
+ 
    }
+ 
}
+
+ 
impl HasAttempts for State {
+ 
    fn attempts(&self) -> Attempts {
+ 
        match self {
+ 
            State::Initial(initial) => initial.attempts,
+ 
            State::Attempted(attempted) => attempted.attempts,
+ 
            State::Connected(connected) => connected.attempts,
+ 
            State::Disconnected(disconnected) => disconnected.attempts,
+ 
        }
+ 
    }
+ 
}
+
+ 
pub struct Sessions {
+ 
    initial: HashMap<NodeId, Session<Initial>>,
+ 
    attempted: HashMap<NodeId, Session<Attempted>>,
+ 
    disconnected: HashMap<NodeId, Session<Disconnected>>,
+ 
    connected: HashMap<NodeId, Session<Connected>>,
+ 
}
+
+ 
impl Sessions {
+ 
    /// Get the number of sessions that are connected and have an [inbound]
+ 
    /// link.
+ 
    ///
+ 
    /// [inbound]: Link::Inbound
+ 
    pub fn connected_inbound(&self) -> usize {
+ 
        self.connected
+ 
            .values()
+ 
            .filter(|session| session.link().is_inbound())
+ 
            .count()
+ 
    }
+
+ 
    /// Get the number of sessions that are connected and have an [outbound]
+ 
    /// link.
+ 
    ///
+ 
    /// [outbound]: Link::Outbound
+ 
    pub fn connected_outbound(&self) -> usize {
+ 
        self.connected
+ 
            .values()
+ 
            .filter(|session| session.link().is_outbound())
+ 
            .count()
+ 
    }
+
+ 
    /// Checks that an existing [`Session`] exists for the given [`NodeId`].
+ 
    pub fn has_session_for(&self, node: &NodeId) -> bool {
+ 
        self.initial.contains_key(node)
+ 
            || self.attempted.contains_key(node)
+ 
            || self.disconnected.contains_key(node)
+ 
            || self.connected.contains_key(node)
+ 
    }
+
+ 
    /// Get all [`Session`]s that are in the [`Connected`] state, along with
+ 
    /// their [`NodeId`]s.
+ 
    pub fn connected(&self) -> impl Iterator<Item = (&NodeId, &Session<Connected>)> {
+ 
        self.connected.iter()
+ 
    }
+
+ 
    /// Transition the [`Session`], identified by the [`NodeId`], to the
+ 
    /// [`Attempted`] state.
+ 
    ///
+ 
    /// If the [`Session`] does not exist, then `None` is returned.
+ 
    pub fn session_to_attempted(&mut self, node: &NodeId) -> Option<Session<Attempted>> {
+ 
        let s = self.initial.remove(node)?.into_attempted();
+ 
        self.attempted.insert(*node, s.clone());
+ 
        Some(s)
+ 
    }
+
+ 
    /// Transition the [`Session`], identified by the [`NodeId`], to the
+ 
    /// [`Disconnected`] state.
+ 
    ///
+ 
    /// The time this [`Session`] was disconnected is marked by `since`, and if
+ 
    /// the connection should be retried then a `retry_at` value should be
+ 
    /// provided.
+ 
    ///
+ 
    /// If the [`Session`] does not exist, then `None` is returned.
+ 
    pub fn session_to_disconnected(
+ 
        &mut self,
+ 
        node: &NodeId,
+ 
        since: LocalTime,
+ 
        retry_at: Option<LocalTime>,
+ 
    ) -> Option<Session<Disconnected>> {
+ 
        match self.remove_session(node) {
+ 
            None => None,
+ 
            Some(session) => {
+ 
                let s = session.into_disconnected(since, retry_at);
+ 
                self.disconnected.insert(*node, s.clone());
+ 
                Some(s)
+ 
            }
+ 
        }
+ 
    }
+
+ 
    /// Transition the [`Session`], identified by the [`NodeId`], to the
+ 
    /// [`Connected`] state.
+ 
    ///
+ 
    /// The [`Session`] is last active given by the time given for `now`, the
+ 
    /// type of [`Link`] is also marked by the provided value, and also keep
+ 
    /// track of whether the session should be persisted.
+ 
    ///
+ 
    /// If the [`Session`] does not exist, then `None` is returned.
+ 
    pub fn session_to_connected(
+ 
        &mut self,
+ 
        node: &NodeId,
+ 
        now: LocalTime,
+ 
        link: Link,
+ 
        persistent: bool,
+ 
    ) -> Option<Session<Connected>> {
+ 
        let s = self.remove_session(node)?;
+ 
        let state = match s.state {
+ 
            State::Initial(initial) => Connected::from_initial(initial, now),
+ 
            State::Attempted(attempted) => Connected::from_attempted(attempted, now),
+ 
            State::Connected(connected) => connected,
+ 
            State::Disconnected(disconnected) => Connected::from_disconnected(disconnected, now),
+ 
        };
+ 
        Some(Session {
+ 
            state,
+ 
            id: s.id,
+ 
            addr: s.addr,
+ 
            link,
+ 
            persistent,
+ 
            last_active: now,
+ 
            subscribe: s.subscribe,
+ 
        })
+ 
    }
+
+ 
    /// Transition a [`Disconnected`] [`Session`] into an [`Initial`] state,
+ 
    /// meaning that it should be re-connected to.
+ 
    ///
+ 
    /// If the [`NodeId`] was not in a [`Disconnected`] state then `None` is
+ 
    /// returned.
+ 
    pub fn reconnect(&mut self, node: &NodeId) -> Option<Session<Initial>> {
+ 
        let s = self.disconnected.remove(node)?.into_initial();
+ 
        self.initial.insert(*node, s.clone());
+ 
        Some(s)
+ 
    }
+
+ 
    /// Get a [`Session`] that can be in any [`State`].
+ 
    pub fn get_session(&self, node: &NodeId) -> Option<Session<State>> {
+ 
        self.initial
+ 
            .get(node)
+ 
            .cloned()
+ 
            .map(|s| s.into_any_state())
+ 
            .or_else(|| {
+ 
                self.attempted
+ 
                    .get(node)
+ 
                    .cloned()
+ 
                    .map(|s| s.into_any_state())
+ 
            })
+ 
            .or_else(|| {
+ 
                self.disconnected
+ 
                    .get(node)
+ 
                    .cloned()
+ 
                    .map(|s| s.into_any_state())
+ 
            })
+ 
            .or_else(|| {
+ 
                self.connected
+ 
                    .get(node)
+ 
                    .cloned()
+ 
                    .map(|s| s.into_any_state())
+ 
            })
+ 
    }
+
+ 
    fn remove_session(&mut self, node: &NodeId) -> Option<Session<State>> {
+ 
        self.initial
+ 
            .remove(node)
+ 
            .map(|s| s.into_any_state())
+ 
            .or_else(|| self.attempted.remove(node).map(|s| s.into_any_state()))
+ 
            .or_else(|| self.disconnected.remove(node).map(|s| s.into_any_state()))
+ 
            .or_else(|| self.connected.remove(node).map(|s| s.into_any_state()))
+ 
    }
+
+ 
    /// Get the [`Session`], for the given [`NodeId`], that is expected to be in
+ 
    /// the [`Connected`] state.
+ 
    pub fn get_connected(&self, node: &NodeId) -> Option<&Session<Connected>> {
+ 
        self.connected.get(node)
+ 
    }
+
+ 
    #[allow(unused)]
+ 
    fn inbound(&mut self, node: NodeId, addr: Address, persistent: bool, now: LocalTime) {
+ 
        self.connected
+ 
            .insert(node, Session::inbound(node, addr, persistent, now));
+ 
    }
+ 
}
+
+ 
pub trait HasAttempts {
+ 
    fn attempts(&self) -> Attempts;
+ 
}
+
+ 
#[derive(Clone, Copy, Debug, PartialEq, Eq, PartialOrd, Ord, Hash)]
+ 
pub struct Attempts {
+ 
    /// Connection attempts. For persistent peers, Tracks
+ 
    /// how many times we've attempted to connect. We reset this to zero
+ 
    /// upon successful connection, once the connection is stable.
+ 
    attempts: usize,
+ 
}
+
+ 
impl Attempts {
+ 
    fn new(attempts: usize) -> Self {
+ 
        Attempts { attempts }
+ 
    }
+
+ 
    pub fn attempted(self) -> Self {
+ 
        Self {
+ 
            attempts: self.attempts + 1,
+ 
        }
+ 
    }
+
+ 
    pub fn reset(&mut self) {
+ 
        self.attempts = 0;
+ 
    }
+
+ 
    pub fn attempts(&self) -> usize {
+ 
        self.attempts
+ 
    }
+
+ 
    pub(super) fn as_u32(&self) -> u32 {
+ 
        self.attempts as u32
+ 
    }
+ 
}
+
+ 
#[derive(Debug, Clone, PartialEq, Eq)]
+ 
pub struct Session<S> {
+ 
    /// The [`NodeId`] of the session.
+ 
    id: NodeId,
+ 
    /// The public protocol [`Address`] for the session.
+ 
    addr: Address,
+ 
    /// The [`Link`] direction for the session.
+ 
    link: Link,
+ 
    /// Keep track of whether the session should be persisted. That is, if it is
+ 
    /// disconnected, re-connection attempts should be made.
+ 
    persistent: bool,
+ 
    /// Last time a message was received from the peer.
+ 
    last_active: LocalTime,
+ 
    /// Peer subscription.
+ 
    subscribe: Option<message::Subscribe>,
+ 
    /// The state the session is in. Can be in the following states:
+ 
    ///   - [`Initial`]
+ 
    ///   - [`Attempted`]
+ 
    ///   - [`Disconnected`]
+ 
    ///   - [`Connected`]
+ 
    state: S,
+ 
}
+
+ 
impl<S: HasAttempts> HasAttempts for Session<S> {
+ 
    fn attempts(&self) -> Attempts {
+ 
        self.state.attempts()
+ 
    }
+ 
}
+
+ 
impl<S> Session<S> {
+ 
    pub fn node(&self) -> NodeId {
+ 
        self.id
+ 
    }
+
+ 
    pub fn address(&self) -> &Address {
+ 
        &self.addr
+ 
    }
+
+ 
    /// Set the [`message::Subscribe`] of this [`Session`].
+ 
    pub fn set_subscription(&mut self, subscription: message::Subscribe) {
+ 
        self.subscribe = Some(subscription);
+ 
    }
+
+ 
    /// Subscribe to the given [`RepoId`], if the [`message::Subscribe`] has
+ 
    /// been set.
+ 
    pub fn subscribe_to(&mut self, rid: &RepoId) {
+ 
        if let Some(ref mut sub) = self.subscribe {
+ 
            sub.filter.insert(rid);
+ 
        }
+ 
    }
+
+ 
    pub fn last_active(&self) -> &LocalTime {
+ 
        &self.last_active
+ 
    }
+
+ 
    pub fn link(&self) -> &Link {
+ 
        &self.link
+ 
    }
+
+ 
    pub fn as_outbound(&mut self) {
+ 
        self.link = Link::Outbound;
+ 
    }
+
+ 
    pub fn into_disconnected(
+ 
        self,
+ 
        since: LocalTime,
+ 
        retry_at: Option<LocalTime>,
+ 
    ) -> Session<Disconnected>
+ 
    where
+ 
        S: HasAttempts,
+ 
    {
+ 
        self.map(|s| Disconnected {
+ 
            since,
+ 
            retry_at,
+ 
            attempts: s.attempts(),
+ 
        })
+ 
    }
+
+ 
    #[allow(unused)]
+ 
    fn seen(&mut self, since: LocalTime) {
+ 
        self.last_active = since;
+ 
    }
+
+ 
    fn into_any_state<T>(self) -> Session<T>
+ 
    where
+ 
        T: From<S>,
+ 
    {
+ 
        self.map(|state| state.into())
+ 
    }
+
+ 
    fn map<T, F>(self, f: F) -> Session<T>
+ 
    where
+ 
        F: FnOnce(S) -> T,
+ 
    {
+ 
        Session {
+ 
            id: self.id,
+ 
            addr: self.addr,
+ 
            link: self.link,
+ 
            persistent: self.persistent,
+ 
            last_active: self.last_active,
+ 
            subscribe: self.subscribe,
+ 
            state: f(self.state),
+ 
        }
+ 
    }
+ 
}
+
+ 
#[derive(Clone, Copy, Debug, PartialEq, Eq, PartialOrd, Ord, Hash)]
+ 
pub struct Initial {
+ 
    attempts: Attempts,
+ 
}
+
+ 
impl Initial {
+ 
    pub fn new() -> Self {
+ 
        Self::with_attempts(Attempts::new(1))
+ 
    }
+
+ 
    pub fn with_attempts(attempts: Attempts) -> Self {
+ 
        Self { attempts }
+ 
    }
+ 
}
+
+ 
impl Default for Initial {
+ 
    fn default() -> Self {
+ 
        Self::new()
+ 
    }
+ 
}
+
+ 
impl Session<Initial> {
+ 
    pub fn outbound(id: NodeId, addr: Address, persistent: bool, last_active: LocalTime) -> Self {
+ 
        Self {
+ 
            id,
+ 
            addr,
+ 
            link: Link::Outbound,
+ 
            persistent,
+ 
            state: Initial::new(),
+ 
            last_active,
+ 
            subscribe: None,
+ 
        }
+ 
    }
+
+ 
    /// Transition the [`Session`] to an [`Attempted`] state, incrementing the
+ 
    /// number of attempts made.
+ 
    pub fn into_attempted(self) -> Session<Attempted> {
+ 
        self.map(|s| Attempted::new(s.attempts.attempted()))
+ 
    }
+
+ 
    /// Transition the [`Session`] into the [`Connected`] state.
+ 
    pub fn into_connected(self, since: LocalTime) -> Session<Connected> {
+ 
        self.map(|s| Connected::new(since, s.attempts))
+ 
    }
+ 
}
+
+ 
#[derive(Clone, Copy, Debug)]
+ 
pub struct Attempted {
+ 
    attempts: Attempts,
+ 
}
+
+ 
impl Attempted {
+ 
    pub fn new(attempts: Attempts) -> Self {
+ 
        Attempted { attempts }
+ 
    }
+ 
}
+
+ 
impl Session<Attempted> {
+ 
    /// Transition the [`Session`] into the [`Connected`] state.
+ 
    pub fn into_connected(self, since: LocalTime) -> Session<Connected> {
+ 
        self.map(|s| Connected::new(since, s.attempts))
+ 
    }
+ 
}
+
+ 
#[derive(Debug, Clone, PartialEq, Eq)]
+ 
pub struct Connected {
+ 
    /// Connected since this time.
+ 
    since: LocalTime,
+ 
    /// Ping state.
+ 
    ping: PingState,
+ 
    /// Ongoing fetches.
+ 
    fetching: HashSet<RepoId>,
+ 
    /// Measured latencies for this peer.
+ 
    latencies: VecDeque<LocalDuration>,
+ 
    /// Whether the connection is stable.
+ 
    stable: bool,
+ 
    /// Number of attempts over the lifetime of the connection. This includes if
+ 
    /// the connection is degraded back to an [`Initial`] state through a
+ 
    /// [`Session::reconnect`].
+ 
    attempts: Attempts,
+ 
}
+
+ 
impl HasAttempts for Connected {
+ 
    fn attempts(&self) -> Attempts {
+ 
        self.attempts
+ 
    }
+ 
}
+
+ 
impl Connected {
+ 
    /// Create a new [`Connected`] state, where `since` is the time of
+ 
    /// connection, and `attempts` is the number of attempted connections in the
+ 
    /// lifetime of the [`Session`].
+ 
    pub fn new(since: LocalTime, attempts: Attempts) -> Self {
+ 
        Self {
+ 
            since,
+ 
            ping: PingState::default(),
+ 
            fetching: HashSet::default(),
+ 
            latencies: VecDeque::default(),
+ 
            stable: false,
+ 
            attempts,
+ 
        }
+ 
    }
+
+ 
    /// Create a fresh [`Connected`] state, using `since` as the [`LocalTime`] for
+ 
    /// when this connection was made.
+ 
    pub fn fresh(since: LocalTime) -> Self {
+ 
        Self::new(since, Attempts::new(0))
+ 
    }
+
+ 
    fn from_initial(initial: Initial, since: LocalTime) -> Self {
+ 
        Self::new(since, initial.attempts)
+ 
    }
+
+ 
    fn from_attempted(attempted: Attempted, since: LocalTime) -> Self {
+ 
        Self::new(since, attempted.attempts)
+ 
    }
+
+ 
    fn from_disconnected(disconnected: Disconnected, since: LocalTime) -> Self {
+ 
        Self::new(since, disconnected.attempts)
+ 
    }
+ 
}
+
+ 
pub struct Ping {
+ 
    since: LocalTime,
+ 
    rng: fastrand::Rng,
+ 
}
+
+ 
impl Session<Connected> {
+ 
    pub fn inbound(id: NodeId, addr: Address, persistent: bool, now: LocalTime) -> Self {
+ 
        Self {
+ 
            id,
+ 
            addr,
+ 
            link: Link::Inbound,
+ 
            persistent,
+ 
            last_active: now,
+ 
            subscribe: None,
+ 
            state: Connected::fresh(now),
+ 
        }
+ 
    }
+
+ 
    /// Checks if the [`Session`] is inactive, i.e. the time passed is greater
+ 
    /// than the `delta`.
+ 
    pub fn is_inactive(&self, now: &LocalTime, delta: LocalDuration) -> bool {
+ 
        *now - self.last_active >= delta
+ 
    }
+
+ 
    pub fn ping(&mut self, mut ping: Ping) -> message::Ping {
+ 
        let msg = message::Ping::new(&mut ping.rng);
+ 
        self.state.ping = PingState::AwaitingResponse {
+ 
            len: msg.ponglen,
+ 
            since: ping.since,
+ 
        };
+ 
        msg
+ 
    }
+
+ 
    pub fn idle(&mut self, now: LocalTime, stable_threshold: LocalDuration) {
+ 
        let Connected {
+ 
            since,
+ 
            ref mut stable,
+ 
            ref mut attempts,
+ 
            ..
+ 
        } = self.state;
+ 
        if now >= since && now.duration_since(since) >= stable_threshold {
+ 
            *stable = true;
+ 
            attempts.reset();
+ 
        }
+ 
    }
+ 
}
+
+ 
#[derive(Clone, Copy, Debug)]
+ 
pub struct Disconnected {
+ 
    /// Since when has this peer been disconnected.
+ 
    since: LocalTime,
+ 
    /// When to retry the connection.
+ 
    retry_at: Option<LocalTime>,
+ 
    /// Number of attempts while disconnected.
+ 
    attempts: Attempts,
+ 
}
+
+ 
impl Session<Disconnected> {
+ 
    pub fn disconnected_since(&self) -> &LocalTime {
+ 
        &self.state.since
+ 
    }
+
+ 
    pub fn should_retry_at(&self) -> Option<&LocalTime> {
+ 
        self.state.retry_at.as_ref()
+ 
    }
+
+ 
    /// Transition the [`Session`] to an [`Initial`] state.
+ 
    fn into_initial(self) -> Session<Initial> {
+ 
        self.map(|s| Initial::with_attempts(s.attempts))
+ 
    }
+ 
}
modified crates/radicle-protocol/src/lib.rs
@@ -4,6 +4,7 @@ pub mod service;
pub mod wire;

pub mod worker;
+ 
pub mod connections;

pub mod tasks;



/// Peer-to-peer protocol version.