More complete Peer distribution

Slightly better implementation of peers, still need to create a more generic system for deciding which components to distribute where and then use that for Peers.

src/game/net.rs

@@ -2,13 +2,16 @@ use bevy::prelude::*;
 
 use crate::net::prelude::*;
 
-pub fn handle_new_peer(new_peers: Query<&Peer, Added<Peer>>) {
+pub fn handle_new_peer(new_peers: Query<&PeerID, Added<Peer>>) {
     for peer in new_peers {
         info!("Peer {} was added", peer.id);
     }
 }
 
-pub fn handle_deleted_peer(mut old_peers: RemovedComponents<Peer>, peers: Query<&Peer>) -> Result {
+pub fn handle_deleted_peer(
+    mut old_peers: RemovedComponents<Peer>,
+    peers: Query<&PeerID>,
+) -> Result {
     for entity in old_peers.read() {
         if let Ok(peer) = peers.get(entity) {
             info!("Peer {} was removed", peer.id);
@@ -20,7 +23,7 @@ pub fn handle_deleted_peer(mut old_peers: RemovedComponents<Peer>, peers: Query<
 }
 
 pub fn handle_incoming_packets(mut packets: EventReader<InboundPacket>) {
-    for packet in packets.read() {
-        info!("Packet received: {:?}", packet.0.message);
+    for InboundPacket(packet) in packets.read() {
+        info!("Packet received: {:?}", packet.message);
     }
 }

src/game/plugin.rs

@@ -13,7 +13,10 @@ use super::{
         check_for_seed, setup_balls, setup_camera, setup_from_seed, setup_player, setup_walls,
     },
     state::AppState,
-    ui::{setup_peer_ui, setup_seed_ui, update_peer_ui, update_peer_ui_timings, update_seed_ui},
+    ui::{
+        setup_peer_ui, setup_potential_peer_ui, setup_seed_ui, update_peer_ui,
+        update_peer_ui_timings, update_potential_peer_ui, update_seed_ui,
+    },
 };
 
 #[derive(Debug, Clone, Copy)]
@@ -55,11 +58,20 @@ impl GamePlugin {
 impl Plugin for GamePlugin {
     fn build(&self, app: &mut App) {
         app.add_plugins((
-            NetIOPlugin::new(self.port, self.source.try_to_address()),
+            NetIOPlugin::maybe_peer(self.port, self.source.try_to_address()),
+            distribution_plugin::<Seed>,
             PhysicsPlugins::default().with_length_unit(50.0),
         ))
         .init_state::<AppState>()
-        .add_systems(Startup, (setup_camera, setup_seed_ui, setup_peer_ui))
+        .add_systems(
+            Startup,
+            (
+                setup_camera,
+                setup_seed_ui,
+                setup_peer_ui,
+                setup_potential_peer_ui,
+            ),
+        )
         .add_systems(
             OnEnter(AppState::InGame),
             (
@@ -75,8 +87,7 @@ impl Plugin for GamePlugin {
                     handle_new_peer,
                     handle_deleted_peer,
                     handle_incoming_packets,
-                )
-                    .run_if(in_state(NetworkState::MultiPlayer)),
+                ),
             ),
         )
         .add_systems(
@@ -85,14 +96,15 @@ impl Plugin for GamePlugin {
                 ((move_player, move_camera).chain(), zoom_camera)
                     .run_if(in_state(AppState::InGame)),
                 update_seed_ui,
-                (update_peer_ui, update_peer_ui_timings)
-                    .run_if(in_state(NetworkState::MultiPlayer)),
+                (
+                    update_peer_ui,
+                    update_peer_ui_timings,
+                    update_potential_peer_ui,
+                ),
                 quit.run_if(input_pressed(KeyCode::KeyQ)),
             ),
         );
 
-        Seed::register(app);
-
         match self.source {
             DataSource::Address(peer) => {
                 info!("Will retrieve seed from peer => {peer}");

src/game/seed.rs

@@ -61,7 +61,7 @@ impl From<Seed> for Vec<u8> {
 impl TryFrom<Vec<u8>> for Seed {
     type Error = TryFromSliceError;
 
-    fn try_from(value: Vec<u8>) -> Result<Self, Self::Error> {
+    fn try_from(value: Vec<u8>) -> std::result::Result<Self, Self::Error> {
         Ok(TryInto::<[u8; 8]>::try_into(value.as_slice())?.into())
     }
 }

src/game/ui.rs

@@ -1,6 +1,6 @@
 use bevy::prelude::*;
 
-use crate::net::prelude::{Peer, PeerReceiveTiming, PeerSendTiming};
+use crate::net::prelude::{Peer, PeerID, PeerReceiveTiming, PeerSendTiming, PotentialPeers};
 
 use super::seed::Seed;
 
@@ -54,11 +54,11 @@ pub fn setup_peer_ui(mut commands: Commands) {
 }
 
 #[derive(Component)]
-pub struct PeerID(Entity);
+pub struct UIPeerID(Entity);
 
 pub fn update_peer_ui(
     ui: Query<(Entity, &Children), With<PeerUI>>,
-    rows: Query<&PeerID>,
+    rows: Query<&UIPeerID>,
     added: Query<Entity, Added<Peer>>,
     mut removed: RemovedComponents<Peer>,
     mut commands: Commands,
@@ -67,14 +67,14 @@ pub fn update_peer_ui(
         for addition in added {
             commands
                 .entity(table)
-                .with_child((Text::new("---- ---- ----"), PeerID(addition)));
+                .with_child((Text::new("---- ---- ----"), UIPeerID(addition)));
         }
         for removal in removed.read() {
             for child in children {
-                if let Ok(id) = rows.get(*child) {
-                    if id.0 == removal {
-                        commands.entity(*child).despawn();
-                    }
+                if let Ok(&UIPeerID(id)) = rows.get(*child)
+                    && id == removal
+                {
+                    commands.entity(*child).despawn();
                 }
             }
         }
@@ -82,12 +82,12 @@ pub fn update_peer_ui(
 }
 
 pub fn update_peer_ui_timings(
-    rows: Query<(&mut Text, &PeerID)>,
-    peers: Query<(&Peer, &PeerReceiveTiming, &PeerSendTiming)>,
+    rows: Query<(&mut Text, &UIPeerID)>,
+    peers: Query<(&PeerID, &PeerReceiveTiming, &PeerSendTiming)>,
     time: Res<Time>,
 ) {
-    for (mut row, id) in rows {
-        if let Ok((peer, recv, send)) = peers.get(id.0) {
+    for (mut row, &UIPeerID(id)) in rows {
+        if let Ok((peer, recv, send)) = peers.get(id) {
             **row = format!(
                 "{} {:.2} {:.2}",
                 peer.id,
@@ -97,3 +97,34 @@ pub fn update_peer_ui_timings(
         }
     }
 }
+
+#[derive(Component, Debug)]
+pub struct PotentialPeerUI;
+
+pub fn setup_potential_peer_ui(mut commands: Commands) {
+    commands
+        .spawn((
+            Text::new("Potential peers:"),
+            Node {
+                position_type: PositionType::Absolute,
+                bottom: Val::Px(5.0),
+                right: Val::Px(5.0),
+                ..default()
+            },
+        ))
+        .with_child((TextSpan::new(""), PotentialPeerUI));
+}
+
+pub fn update_potential_peer_ui(
+    potential_peers: Res<PotentialPeers>,
+    text: Query<&mut TextSpan, With<PotentialPeerUI>>,
+) {
+    for mut span in text {
+        **span = potential_peers
+            .addresses
+            .iter()
+            .map(|addr| addr.to_string())
+            .collect::<Vec<String>>()
+            .join("\n");
+    }
+}

src/lib.rs

@@ -15,7 +15,7 @@ use game::prelude::*;
 /// Also functions as a Bevy plugin to pass the configuration into the app.
 #[derive(Parser)]
 #[command(version, about)]
-pub struct AppSettings {
+pub struct AppSettingsPlugin {
     #[command(flatten)]
     source: Source,
 
@@ -36,7 +36,7 @@ struct Source {
     connect: Option<SocketAddr>,
 }
 
-impl Plugin for AppSettings {
+impl Plugin for AppSettingsPlugin {
     fn build(&self, app: &mut App) {
         app.insert_resource(Gravity(Vector::ZERO)).add_plugins((
             DefaultPlugins.set(WindowPlugin {

src/main.rs

@@ -1,8 +1,8 @@
 use bevy::prelude::{App, AppExit};
 use clap::Parser;
 
-use distributed_physics_test::AppSettings;
+use distributed_physics_test::AppSettingsPlugin;
 
 fn main() -> AppExit {
-    App::new().add_plugins(AppSettings::parse()).run()
+    App::new().add_plugins(AppSettingsPlugin::parse()).run()
 }

src/net/distribution.rs

@@ -2,48 +2,32 @@ use bevy::prelude::*;
 
 use super::{
     packet::{InboundPacket, OutboundPacket, Packet},
-    peer::Peer,
-    state::NetworkState,
+    peer::{Peer, PeerID},
 };
 
 fn spawner<T: TryFrom<Vec<u8>> + Component>(
     mut inbound: EventReader<InboundPacket>,
     mut commands: Commands,
 ) {
-    for packet in inbound.read() {
-        if let Ok(entity) = T::try_from(packet.0.message.clone()) {
+    for InboundPacket(packet) in inbound.read() {
+        if let Ok(entity) = T::try_from(packet.message.clone()) {
             commands.spawn(entity);
         }
     }
 }
 
 fn sender<T: Into<Vec<u8>> + Component + Clone>(
-    peers: Query<&Peer, Added<Peer>>,
+    peers: Query<&PeerID, Added<Peer>>,
     entities: Query<&T>,
     mut outbound: EventWriter<OutboundPacket>,
 ) {
     for peer in peers {
         for entity in entities {
-            outbound.write(OutboundPacket(Packet::new(
-                (*entity).clone().into(),
-                peer.id,
-            )));
+            outbound.write(Packet::create((*entity).clone().into(), peer.id));
         }
     }
 }
 
-pub trait Networked: Into<Vec<u8>> + TryFrom<Vec<u8>> + Component + Clone {
-    fn register(app: &mut App);
-}
-
-impl<T> Networked for T
-where
-    T: Into<Vec<u8>> + TryFrom<Vec<u8>> + Component + Clone,
-{
-    fn register(app: &mut App) {
-        app.add_systems(
-            FixedUpdate,
-            (sender::<T>, spawner::<T>).run_if(in_state(NetworkState::MultiPlayer)),
-        );
-    }
+pub fn distribution_plugin<T: Into<Vec<u8>> + TryFrom<Vec<u8>> + Component + Clone>(app: &mut App) {
+    app.add_systems(FixedUpdate, (sender::<T>, spawner::<T>));
 }

src/net/heartbeat.rs

@@ -0,0 +1,77 @@
+use std::time::Duration;
+
+use bevy::prelude::*;
+
+use crate::net::{packet::PacketType, peer::PotentialPeers};
+
+use super::{
+    io::{Config, format_message},
+    packet::{OutboundPacket, Packet},
+    peer::{Peer, PeerChangeEvent, PeerID, PeerReceiveTiming, PeerSendTiming},
+    queues::NetworkSend,
+};
+
+const PING_FREQUENCY: Duration = Duration::from_secs(3);
+const MISSED_PINGS: u32 = 3;
+
+// TODO: Perhaps this needs a state rethink, is Single/Multiplayer actually useful vs Disconnected, Connecting, Connected?
+// Would also help to state-scope some of these things, like InitialAddresses vs PeerMap
+pub fn heartbeat(
+    peers: Query<(&PeerID, &PeerSendTiming)>,
+    time: Res<Time>,
+    mut outbound: EventWriter<OutboundPacket>,
+) -> Result {
+    for (peer, last) in peers {
+        // Allow for 2 consecutive missed heartbeats without timing out
+        if last.time() + PING_FREQUENCY > time.elapsed() {
+            continue;
+        }
+        outbound.write(Packet::create(Vec::new(), peer.id));
+    }
+    Ok(())
+}
+
+pub fn timeout(
+    peers: Query<(&PeerID, &PeerReceiveTiming), With<Peer>>, // I mean... With<Peer> is inherent, but I guess I'll keep it as that might change
+    time: Res<Time>,
+    mut delete: EventWriter<PeerChangeEvent>,
+) {
+    for (peer, last) in peers {
+        if last.time() + PING_FREQUENCY * MISSED_PINGS < time.elapsed() {
+            warn!("Peer {} timed out", peer.id);
+            delete.write(PeerChangeEvent::new(peer.id, None));
+        }
+    }
+}
+
+#[derive(Debug, Resource)]
+pub struct PotentialPeerTimer {
+    timer: Timer,
+}
+
+impl Default for PotentialPeerTimer {
+    fn default() -> Self {
+        Self {
+            timer: Timer::new(PING_FREQUENCY, TimerMode::Repeating),
+        }
+    }
+}
+
+pub fn ping_potential_peers(
+    mut timer: ResMut<PotentialPeerTimer>,
+    time: Res<Time>,
+    peers: Res<PotentialPeers>,
+    to_socket: Res<NetworkSend>,
+    config: Res<Config>,
+) -> Result {
+    timer.timer.tick(time.delta());
+    if timer.timer.finished() {
+        for peer in &peers.addresses {
+            to_socket.send(
+                format_message(&Vec::new(), PacketType::Peer, config.id),
+                *peer,
+            )?;
+        }
+    }
+    Ok(())
+}

src/net/io.rs

@@ -1,16 +1,29 @@
-use std::time::Duration;
-
 use bevy::prelude::*;
 use uuid::Uuid;
 
-use crate::net::peer::PotentialPeer;
+use crate::net::packet::PacketType;
 
 use super::{
     packet::{InboundPacket, OutboundPacket, Packet},
-    peer::{Peer, PeerChangeEvent, PeerData, PeerMap, PeerReceiveTiming, PeerSendTiming},
+    peer::{PeerChangeEvent, PeerData, PeerMap, PeerReceiveTiming, PeerSendTiming},
     queues::{NetworkReceive, NetworkSend},
 };
 
+#[derive(Debug, Resource)]
+pub struct Config {
+    pub id: Uuid,
+}
+
+impl Default for Config {
+    fn default() -> Self {
+        Self { id: Uuid::new_v4() }
+    }
+}
+
+pub fn format_message(data: &Vec<u8>, variant: PacketType, id: Uuid) -> Vec<u8> {
+    [data.as_slice(), &[variant as u8], id.as_bytes()].concat()
+}
+
 pub fn handle_network_input(
     from_socket: Res<NetworkReceive>,
     peer_map: Res<PeerMap>,
@@ -19,26 +32,24 @@ pub fn handle_network_input(
     time: Res<Time>,
     mut change_peer: EventWriter<PeerChangeEvent>,
 ) -> Result {
-    for (mut message, address) in from_socket.iter() {
-        if message.len() < 16 {
-            return Err(format!(
-                "Message of length {} is not large enough to contain UUID",
-                message.len()
-            )
-            .into());
-        }
-        let uuid = Uuid::from_slice(message.split_off(message.len() - 16).as_slice())?;
-        if !message.is_empty() {
-            to_app.write(InboundPacket(Packet::new(message, uuid)));
-        }
-        if let Some(peer_id) = peer_map.get(&uuid) {
-            let (peer, mut last) = peers.get_mut(*peer_id)?;
-            last.update(&time);
-            if address == peer.addr {
-                continue;
+    for (message, address) in from_socket.iter() {
+        match Packet::try_from(message) {
+            Ok(packet) => {
+                // TODO: Handle packet variant
+                if !packet.message.is_empty() {
+                    to_app.write(packet.clone().into());
+                }
+                if let Some(peer_id) = peer_map.get(&packet.peer) {
+                    let (peer, mut last) = peers.get_mut(*peer_id)?;
+                    last.update(&time);
+                    if address == peer.addr {
+                        continue;
+                    }
+                }
+                change_peer.write(PeerChangeEvent::new(packet.peer, Some(address)));
             }
+            Err(err) => warn!("Error reading packet: {:?}", err),
         }
-        change_peer.write(PeerChangeEvent::new(uuid, Some(address)));
     }
     Ok(())
 }
@@ -47,52 +58,16 @@ pub fn handle_network_output(
     mut from_app: EventReader<OutboundPacket>,
     peer_map: Res<PeerMap>,
     mut peers: Query<(&PeerData, &mut PeerSendTiming)>,
+    config: Res<Config>,
     to_socket: Res<NetworkSend>,
     time: Res<Time>,
 ) -> Result {
-    for packet in from_app.read() {
-        let peer_id = peer_map.try_get(&packet.0.peer)?;
+    for OutboundPacket(packet) in from_app.read() {
+        let peer_id = peer_map.try_get(&packet.peer)?;
         let (peer, mut last) = peers.get_mut(*peer_id)?;
-        // Append our UUID for client identification
-        let message = [packet.0.message.as_slice(), peer.me.as_bytes()].concat();
+        let message = format_message(&packet.message, packet.variant, config.id);
         to_socket.send(message, peer.addr.into())?;
         last.update(&time);
     }
     Ok(())
 }
-
-const TIMEOUT: Duration = Duration::from_secs(10);
-
-pub fn heartbeat(
-    peers: Query<(AnyOf<(&Peer, &PotentialPeer)>, &PeerSendTiming)>,
-    time: Res<Time>,
-    mut outbound: EventWriter<OutboundPacket>,
-) -> Result {
-    for (peer, last) in peers {
-        // Allow for 2 consecutive missed heartbeats without timing out
-        if last.time() + TIMEOUT / 3 > time.elapsed() {
-            continue;
-        }
-        let id = match peer {
-            (None, None) => return Err("No peer identification".into()),
-            (None, Some(potential)) => potential.id,
-            (Some(actual), None) => actual.id,
-            (Some(_), Some(_)) => return Err("Both a potential and actual peer".into()),
-        };
-        outbound.write(OutboundPacket(Packet::new(Vec::new(), id)));
-    }
-    Ok(())
-}
-
-pub fn timeout(
-    peers: Query<(&Peer, &PeerReceiveTiming)>,
-    time: Res<Time>,
-    mut delete: EventWriter<PeerChangeEvent>,
-) {
-    for (peer, last) in peers {
-        if last.time() + TIMEOUT < time.elapsed() {
-            warn!("Peer {} timed out", peer.id);
-            delete.write(PeerChangeEvent::new(peer.id, None));
-        }
-    }
-}

src/net/mod.rs

@@ -1,18 +1,17 @@
 mod distribution;
+mod heartbeat;
 mod io;
 mod packet;
 mod peer;
 mod plugin;
 mod queues;
 mod socket;
-mod state;
 mod thread;
 
 #[allow(unused_imports)]
 pub mod prelude {
-    pub use super::distribution::Networked;
+    pub use super::distribution::distribution_plugin;
     pub use super::packet::{InboundPacket, OutboundPacket, Packet};
-    pub use super::peer::{Peer, PeerReceiveTiming, PeerSendTiming};
+    pub use super::peer::{Peer, PeerID, PeerReceiveTiming, PeerSendTiming, PotentialPeers};
     pub use super::plugin::NetIOPlugin;
-    pub use super::state::NetworkState;
 }

src/net/packet.rs

@@ -2,19 +2,95 @@ use bevy::prelude::*;
 use uuid::Uuid;
 
 #[derive(Debug)]
+pub enum TryFromBytesError {
+    InsufficientLength,
+    NotUUID,
+    NotVariant,
+}
+
+#[derive(Clone, Copy, Debug)]
+pub enum PacketType {
+    Standard = 0x00,
+    Peer = 0x01,
+}
+
+impl From<PacketType> for u8 {
+    fn from(value: PacketType) -> Self {
+        value as u8
+    }
+}
+
+impl TryFrom<u8> for PacketType {
+    type Error = TryFromBytesError;
+
+    fn try_from(value: u8) -> std::result::Result<Self, Self::Error> {
+        match value {
+            value if value == PacketType::Standard as u8 => Ok(PacketType::Standard),
+            value if value == PacketType::Peer as u8 => Ok(PacketType::Peer),
+            _ => Err(TryFromBytesError::NotVariant),
+        }
+    }
+}
+
+pub const UUID_SIZE: usize = 16;
+
+#[derive(Clone, Debug)]
 pub struct Packet {
     pub message: Vec<u8>,
+    pub variant: PacketType,
     pub peer: Uuid,
 }
 
 impl Packet {
-    pub fn new(message: Vec<u8>, peer: Uuid) -> Self {
-        Self { peer, message }
+    pub fn new(message: Vec<u8>, variant: PacketType, peer: Uuid) -> Self {
+        Self {
+            message,
+            variant,
+            peer,
+        }
+    }
+
+    pub fn create<T: From<Packet>>(message: Vec<u8>, peer: Uuid) -> T {
+        Self {
+            message,
+            variant: PacketType::Standard,
+            peer,
+        }
+        .into()
+    }
+}
+
+impl TryFrom<Vec<u8>> for Packet {
+    type Error = TryFromBytesError;
+
+    fn try_from(mut value: Vec<u8>) -> std::result::Result<Self, Self::Error> {
+        if value.len() < UUID_SIZE {
+            return Err(TryFromBytesError::InsufficientLength);
+        }
+        let uuid = Uuid::from_slice(value.split_off(value.len() - UUID_SIZE).as_slice())
+            .map_err(|_| TryFromBytesError::NotUUID)?;
+        let variant = value
+            .pop()
+            .ok_or(TryFromBytesError::InsufficientLength)?
+            .try_into()?;
+        Ok(Packet::new(value, variant, uuid))
     }
 }
 
 #[derive(Debug, Event)]
 pub struct OutboundPacket(pub Packet);
 
+impl From<Packet> for OutboundPacket {
+    fn from(value: Packet) -> Self {
+        Self(value)
+    }
+}
+
 #[derive(Debug, Event)]
 pub struct InboundPacket(pub Packet);
+
+impl From<Packet> for InboundPacket {
+    fn from(value: Packet) -> Self {
+        Self(value)
+    }
+}

src/net/peer.rs

@@ -1,14 +1,14 @@
 use std::{
     array::TryFromSliceError,
-    collections::HashMap,
-    net::{IpAddr, Ipv6Addr, SocketAddr},
+    collections::{HashMap, HashSet},
+    net::{IpAddr, Ipv4Addr, Ipv6Addr, SocketAddr},
     time::Duration,
 };
 
 use bevy::prelude::*;
 use uuid::Uuid;
 
-use super::packet::{OutboundPacket, Packet};
+use super::packet::{InboundPacket, OutboundPacket, Packet, PacketType};
 
 #[derive(Component, Debug, Default)]
 pub struct PeerSendTiming(Duration);
@@ -40,55 +40,12 @@ impl PeerReceiveTiming {
     }
 }
 
-#[derive(Component, Debug)]
-#[require(PeerData, PeerReceiveTiming)]
-pub struct Peer {
-    pub id: Uuid,
-}
-
-#[derive(Component, Debug)]
-#[require(PeerData)]
-pub struct PotentialPeer {
-    pub id: Uuid,
-}
-
-impl Default for PotentialPeer {
-    fn default() -> Self {
-        Self { id: Uuid::new_v4() }
-    }
-}
-
-#[derive(Clone, Component, Copy, Debug)]
-#[require(PeerSendTiming)]
-pub struct PeerData {
-    pub addr: Address,
-    pub me: Uuid,
-}
-
-impl PeerData {
-    pub fn new(addr: SocketAddr, me: Uuid) -> Self {
-        Self {
-            addr: addr.into(),
-            me,
-        }
-    }
-}
-
-impl Default for PeerData {
-    fn default() -> Self {
-        Self {
-            addr: Default::default(),
-            me: Uuid::new_v4(),
-        }
-    }
-}
-
 #[derive(Clone, Copy, Debug)]
 pub struct Address(SocketAddr);
 
 impl From<Address> for SocketAddr {
-    fn from(value: Address) -> Self {
-        value.0
+    fn from(Address(value): Address) -> Self {
+        value
     }
 }
 
@@ -111,12 +68,12 @@ impl PartialEq<Address> for SocketAddr {
 }
 
 impl From<Address> for Vec<u8> {
-    fn from(value: Address) -> Self {
-        let mut bytes: Vec<u8> = match value.0.ip() {
+    fn from(Address(value): Address) -> Self {
+        let mut bytes: Vec<u8> = match value.ip() {
             IpAddr::V4(ipv4_addr) => ipv4_addr.octets().into(),
             IpAddr::V6(ipv6_addr) => ipv6_addr.octets().into(),
         };
-        bytes.extend(value.0.port().to_le_bytes());
+        bytes.extend(value.port().to_le_bytes());
         bytes
     }
 }
@@ -124,14 +81,25 @@ impl From<Address> for Vec<u8> {
 impl TryFrom<Vec<u8>> for Address {
     type Error = TryFromSliceError;
 
-    fn try_from(value: Vec<u8>) -> Result<Self, Self::Error> {
-        let port = u16::from_le_bytes(TryInto::<[u8; 2]>::try_into(
-            value.clone().split_off(value.len() - 2).as_slice(),
+    fn try_from(value: Vec<u8>) -> std::result::Result<Self, Self::Error> {
+        const PORT_SIZE: usize = 2;
+
+        if value.len() < PORT_SIZE {
+            todo!();
+        }
+        let mut bytes = value.clone();
+        let port = u16::from_le_bytes(TryInto::<[u8; PORT_SIZE]>::try_into(
+            bytes.split_off(bytes.len() - PORT_SIZE).as_slice(),
         )?);
-        let addr = if let Ok(bytes) = TryInto::<[u8; 4]>::try_into(value.as_slice()) {
+        let addr = if let Ok(bytes) =
+            TryInto::<[u8; Ipv4Addr::BITS as usize / 8]>::try_into(bytes.as_slice())
+        {
             SocketAddr::from((bytes, port))
         } else {
-            SocketAddr::from((TryInto::<[u8; 16]>::try_into(value.as_slice())?, port))
+            SocketAddr::from((
+                TryInto::<[u8; Ipv6Addr::BITS as usize / 8]>::try_into(bytes.as_slice())?,
+                port,
+            ))
         };
         Ok(Address(addr))
     }
@@ -143,6 +111,53 @@ impl Default for Address {
     }
 }
 
+#[derive(Clone, Component, Copy, Debug, Default)]
+#[require(PeerSendTiming)]
+pub struct PeerData {
+    pub addr: Address,
+}
+
+impl PeerData {
+    pub fn new(addr: SocketAddr) -> Self {
+        Self { addr: addr.into() }
+    }
+}
+
+#[derive(Component, Debug)]
+#[require(PeerData)]
+pub struct PeerID {
+    pub id: Uuid,
+}
+
+impl PeerID {
+    pub fn new(id: Uuid) -> Self {
+        Self { id }
+    }
+}
+
+impl Default for PeerID {
+    fn default() -> Self {
+        Self { id: Uuid::new_v4() }
+    }
+}
+
+#[derive(Component, Debug)]
+#[require(PeerID, PeerReceiveTiming)]
+pub struct Peer;
+
+#[derive(Debug, Default, Resource)]
+pub struct PotentialPeers {
+    pub addresses: HashSet<SocketAddr>,
+}
+
+impl PotentialPeers {
+    pub fn new(addresses: Vec<SocketAddr>) -> Self {
+        Self {
+            addresses: addresses.into_iter().collect(),
+        }
+    }
+}
+
 #[derive(Debug, Default, Resource)]
 pub struct PeerMap {
     map: HashMap<Uuid, Entity>,
@@ -157,17 +172,13 @@ impl PeerMap {
         self.map.get(uuid)
     }
 
-    pub fn try_get(&self, uuid: &Uuid) -> Result<&Entity, String> {
-        self.get(uuid).ok_or(format!("No entity with uuid: {uuid}"))
+    pub fn try_get(&self, uuid: &Uuid) -> std::result::Result<&Entity, String> {
+        self.get(uuid).ok_or(format!("No peer with uuid: {uuid}"))
     }
 
     pub fn remove(&mut self, uuid: &Uuid) -> Option<Entity> {
         self.map.remove(uuid)
     }
-
-    pub fn len(&self) -> usize {
-        self.map.len()
-    }
 }
 
 #[derive(Debug, Event)]
@@ -186,63 +197,82 @@ pub fn handle_peer_change(
     mut changes: EventReader<PeerChangeEvent>,
     mut peer_map: ResMut<PeerMap>,
     mut peers: Query<&mut PeerData>,
+    mut potential_peers: ResMut<PotentialPeers>,
     mut commands: Commands,
     time: Res<Time>,
 ) -> Result {
     for change in changes.read() {
-        if let Some(entity) = peer_map.get(&change.peer) {
-            if let Some(addr) = change.addr {
+        match (peer_map.get(&change.peer), change.addr) {
+            // Peer modification
+            (Some(entity), Some(addr)) => {
                 if let Ok(mut peer) = peers.get_mut(*entity) {
-                    peer.addr = Address(addr);
+                    peer.addr = addr.into();
                 } else {
                     warn!("Peer {} doesn't exist (just added?)", change.peer);
                 }
-            } else {
+            }
+            // Peer deletion
+            (Some(entity), None) => {
                 commands.get_entity(*entity)?.despawn();
                 peer_map.remove(&change.peer);
             }
-        } else if let Some(addr) = change.addr {
-            info!("Adding peer {} ({})", change.peer, addr);
-            peer_map.insert(
-                change.peer,
-                commands
-                    .spawn((
-                        PeerData::new(addr, Uuid::new_v4()),
-                        PeerReceiveTiming::new(&time),
-                    ))
-                    .id(),
-            );
-        } else {
-            warn!("Peer {} already deleted", change.peer);
+            // Peer addition
+            (None, Some(addr)) => {
+                info!("Adding peer {} ({})", change.peer, addr);
+                peer_map.insert(
+                    change.peer,
+                    commands
+                        .spawn((
+                            Peer,
+                            PeerID::new(change.peer),
+                            PeerData::new(addr),
+                            PeerReceiveTiming::new(&time),
+                        ))
+                        .id(),
+                );
+            }
+            // Double peer deletion
+            (None, None) => warn!("Peer {} already deleted", change.peer),
         }
-    }
-    if peer_map.len() > 1 {
-        if let Some(entity) = peer_map.remove(&Uuid::nil()) {
-            commands.get_entity(entity)?.despawn();
+        if let Some(addr) = change.addr {
+            potential_peers.addresses.remove(&addr);
         }
     }
     Ok(())
 }
 
-#[allow(clippy::type_complexity)]
+pub fn new_peer_message(
+    mut from_network: EventReader<InboundPacket>,
+    peers: Query<&PeerData>,
+    mut potential_peers: ResMut<PotentialPeers>,
+) {
+    'packet: for packet in from_network.read() {
+        if let Ok(addr) = TryInto::<Address>::try_into(packet.0.message.clone()) {
+            if potential_peers.addresses.contains(&addr.into()) {
+                continue;
+            }
+            for peer in peers {
+                if peer.addr == addr.into() {
+                    continue 'packet;
+                }
+            }
+            potential_peers.addresses.insert(addr.into());
+        }
+    }
+}
+
+// TODO: Make this a more generic system
 pub fn handle_new_peer(
-    new_peers: Query<(Option<Ref<Peer>>, Option<&Peer>, &PeerData)>,
+    peers: Query<(Ref<Peer>, &PeerID, &PeerData)>,
     mut outbound: EventWriter<OutboundPacket>,
-) -> Result {
-    for (change, this, data) in new_peers {
-        if let Some(change) = change {
-            if change.is_added() {
-                if let Some(this) = this {
-                    for (_, _, other) in new_peers {
-                        if data.me != other.me {
-                            outbound.write(OutboundPacket(Packet::new(other.addr.into(), this.id)));
-                        }
-                    }
-                } else {
-                    return Err("Ref<Peer> without Peer".into());
+) {
+    for (change, peer, _) in peers {
+        if change.is_added() {
+            for (_, other, data) in peers {
+                if peer.id != other.id {
+                    outbound.write(Packet::new(data.addr.into(), PacketType::Peer, peer.id).into());
                 }
             }
         }
     }
-    Ok(())
 }

src/net/plugin.rs

@@ -1,65 +1,59 @@
 use std::net::SocketAddr;
 
 use bevy::prelude::*;
-use uuid::Uuid;
 
 use super::{
-    io::{handle_network_input, handle_network_output, heartbeat, timeout},
+    heartbeat::{PotentialPeerTimer, heartbeat, ping_potential_peers, timeout},
+    io::{Config, handle_network_input, handle_network_output},
     packet::{InboundPacket, OutboundPacket},
-    peer::{PeerChangeEvent, PeerData, PeerMap, handle_new_peer, handle_peer_change},
+    peer::{
+        PeerChangeEvent, PeerMap, PotentialPeers, handle_new_peer, handle_peer_change,
+        new_peer_message,
+    },
     queues::{NetworkReceive, NetworkSend},
     socket::bind_socket,
-    state::NetworkState,
 };
 
 pub struct NetIOPlugin {
     listen: u16,
-    peer: Option<SocketAddr>,
+    initial_peers: Vec<SocketAddr>,
 }
 
 impl NetIOPlugin {
-    pub fn new(listen: u16, peer: Option<SocketAddr>) -> Self {
-        Self { listen, peer }
+    pub fn maybe_peer(listen: u16, peer: Option<SocketAddr>) -> Self {
+        Self {
+            listen,
+            initial_peers: match peer {
+                Some(addr) => vec![addr],
+                None => Vec::new(),
+            },
+        }
     }
 }
 
 impl Plugin for NetIOPlugin {
     fn build(&self, app: &mut App) {
-        app.init_state::<NetworkState>()
-            .add_systems(
-                FixedPreUpdate,
-                (handle_network_input, handle_peer_change)
-                    .chain()
-                    .run_if(in_state(NetworkState::MultiPlayer)),
-            )
-            .add_systems(
-                FixedUpdate,
-                (heartbeat, timeout, handle_new_peer).run_if(in_state(NetworkState::MultiPlayer)),
-            )
-            .add_systems(
-                FixedPostUpdate,
-                handle_network_output.run_if(in_state(NetworkState::MultiPlayer)),
-            )
-            .add_event::<PeerChangeEvent>()
-            .add_event::<InboundPacket>()
-            .add_event::<OutboundPacket>();
+        app.add_systems(
+            FixedPreUpdate,
+            (handle_network_input, (handle_peer_change, new_peer_message)).chain(),
+        )
+        .add_systems(
+            FixedUpdate,
+            (heartbeat, timeout, handle_new_peer, ping_potential_peers),
+        )
+        .add_systems(FixedPostUpdate, handle_network_output)
+        .init_resource::<Config>()
+        .init_resource::<PeerMap>()
+        .init_resource::<PotentialPeerTimer>()
+        .insert_resource(PotentialPeers::new(self.initial_peers.clone()))
+        .add_event::<PeerChangeEvent>()
+        .add_event::<InboundPacket>()
+        .add_event::<OutboundPacket>();
 
         match bind_socket(self.listen) {
             Ok((send, receive)) => {
-                app.insert_state(NetworkState::MultiPlayer)
-                    .insert_resource(NetworkSend::new(send))
+                app.insert_resource(NetworkSend::new(send))
                     .insert_resource(NetworkReceive::new(receive));
-
-                let mut peer_map = PeerMap::default();
-                if let Some(socket) = self.peer {
-                    let entity = app.world_mut().spawn(PeerData {
-                        addr: socket.into(),
-                        me: Uuid::nil(),
-                    });
-                    peer_map.insert(Uuid::nil(), entity.id());
-                }
-
-                app.insert_resource(peer_map);
             }
             Err(err) => {
                 warn!("Failed to set up networking: {err}");

src/net/state.rs

@@ -1,8 +0,0 @@
-use bevy::prelude::*;
-
-#[derive(States, Default, Debug, Clone, PartialEq, Eq, Hash)]
-pub enum NetworkState {
-    #[default]
-    SinglePlayer,
-    MultiPlayer,
-}