azalea_client/plugins/
join.rs

1use std::{net::SocketAddr, sync::Arc};
2
3use azalea_entity::{LocalEntity, indexing::EntityUuidIndex};
4use azalea_protocol::{
5    ServerAddress,
6    common::client_information::ClientInformation,
7    connect::{Connection, ConnectionError, Proxy},
8    packets::{
9        ClientIntention, ConnectionProtocol, PROTOCOL_VERSION,
10        handshake::ServerboundIntention,
11        login::{ClientboundLoginPacket, ServerboundHello, ServerboundLoginPacket},
12    },
13};
14use azalea_world::Instance;
15use bevy_app::prelude::*;
16use bevy_ecs::prelude::*;
17use bevy_tasks::{IoTaskPool, Task, futures_lite::future};
18use parking_lot::RwLock;
19use tokio::sync::mpsc;
20use tracing::{debug, warn};
21
22use super::events::LocalPlayerEvents;
23use crate::{
24    Account, LocalPlayerBundle,
25    connection::RawConnection,
26    packet::login::{InLoginState, SendLoginPacketEvent},
27};
28
29/// A plugin that allows bots to join servers.
30pub struct JoinPlugin;
31impl Plugin for JoinPlugin {
32    fn build(&self, app: &mut App) {
33        app.add_message::<StartJoinServerEvent>()
34            .add_message::<ConnectionFailedEvent>()
35            .add_systems(
36                Update,
37                (
38                    handle_start_join_server_event.before(super::login::poll_auth_task),
39                    poll_create_connection_task,
40                )
41                    .chain(),
42            );
43    }
44}
45
46/// An event to make a client join the server and be added to our swarm.
47///
48/// This won't do anything if a client with the Account UUID is already
49/// connected to the server.
50#[derive(Message, Debug)]
51pub struct StartJoinServerEvent {
52    pub account: Account,
53    pub connect_opts: ConnectOpts,
54    pub event_sender: Option<mpsc::UnboundedSender<crate::Event>>,
55
56    // this is mpsc instead of oneshot so it can be cloned (since it's sent in an event)
57    pub start_join_callback_tx: Option<mpsc::UnboundedSender<Entity>>,
58}
59
60/// Options for how the connection to the server will be made.
61///
62/// These are persisted on reconnects.
63///
64/// This is inserted as a component on clients to make auto-reconnecting work.
65#[derive(Debug, Clone, Component)]
66pub struct ConnectOpts {
67    pub address: ServerAddress,
68    pub resolved_address: SocketAddr,
69    pub proxy: Option<Proxy>,
70}
71
72/// An event that's sent when creating the TCP connection and sending the first
73/// packet fails.
74///
75/// This isn't sent if we're kicked later, see [`DisconnectEvent`].
76///
77/// [`DisconnectEvent`]: crate::disconnect::DisconnectEvent
78#[derive(Message)]
79pub struct ConnectionFailedEvent {
80    pub entity: Entity,
81    pub error: ConnectionError,
82}
83
84pub fn handle_start_join_server_event(
85    mut commands: Commands,
86    mut events: MessageReader<StartJoinServerEvent>,
87    mut entity_uuid_index: ResMut<EntityUuidIndex>,
88    connection_query: Query<&RawConnection>,
89) {
90    for event in events.read() {
91        let uuid = event.account.uuid_or_offline();
92        let entity = if let Some(entity) = entity_uuid_index.get(&uuid) {
93            debug!("Reusing entity {entity:?} for client");
94
95            // check if it's already connected
96            if let Ok(conn) = connection_query.get(entity)
97                && conn.is_alive()
98            {
99                if let Some(start_join_callback_tx) = &event.start_join_callback_tx {
100                    warn!(
101                        "Received StartJoinServerEvent for {entity:?} but it's already connected. Ignoring the event but replying with Ok."
102                    );
103                    let _ = start_join_callback_tx.send(entity);
104                } else {
105                    warn!(
106                        "Received StartJoinServerEvent for {entity:?} but it's already connected. Ignoring the event."
107                    );
108                }
109                return;
110            }
111
112            entity
113        } else {
114            let entity = commands.spawn_empty().id();
115            debug!("Created new entity {entity:?} for client");
116            // add to the uuid index
117            entity_uuid_index.insert(uuid, entity);
118            entity
119        };
120
121        if let Some(start_join_callback) = &event.start_join_callback_tx {
122            let _ = start_join_callback.send(entity);
123        }
124
125        let mut entity_mut = commands.entity(entity);
126
127        entity_mut.insert((
128            // add the Account to the entity now so plugins can access it earlier
129            event.account.to_owned(),
130            // localentity is always present for our clients, even if we're not actually logged
131            // in
132            LocalEntity,
133            // this is inserted early so the user can always access and modify it
134            ClientInformation::default(),
135            // ConnectOpts is inserted as a component here
136            event.connect_opts.clone(),
137            // we don't insert InLoginState until we actually create the connection. note that
138            // there's no InHandshakeState component since we switch off of the handshake state
139            // immediately when the connection is created
140        ));
141
142        if let Some(event_sender) = &event.event_sender {
143            // this is optional so we don't leak memory in case the user doesn't want to
144            // handle receiving packets
145            entity_mut.insert(LocalPlayerEvents(event_sender.clone()));
146        }
147
148        let task_pool = IoTaskPool::get();
149        let connect_opts = event.connect_opts.clone();
150        let task = task_pool.spawn(async_compat::Compat::new(
151            create_conn_and_send_intention_packet(connect_opts),
152        ));
153
154        entity_mut.insert(CreateConnectionTask(task));
155    }
156}
157
158async fn create_conn_and_send_intention_packet(
159    opts: ConnectOpts,
160) -> Result<LoginConn, ConnectionError> {
161    let mut conn = if let Some(proxy) = opts.proxy {
162        Connection::new_with_proxy(&opts.resolved_address, proxy).await?
163    } else {
164        Connection::new(&opts.resolved_address).await?
165    };
166
167    conn.write(ServerboundIntention {
168        protocol_version: PROTOCOL_VERSION,
169        hostname: opts.address.host.clone(),
170        port: opts.address.port,
171        intention: ClientIntention::Login,
172    })
173    .await?;
174
175    let conn = conn.login();
176
177    Ok(conn)
178}
179
180type LoginConn = Connection<ClientboundLoginPacket, ServerboundLoginPacket>;
181
182#[derive(Component)]
183pub struct CreateConnectionTask(pub Task<Result<LoginConn, ConnectionError>>);
184
185pub fn poll_create_connection_task(
186    mut commands: Commands,
187    mut query: Query<(Entity, &mut CreateConnectionTask, &Account)>,
188    mut connection_failed_events: MessageWriter<ConnectionFailedEvent>,
189) {
190    for (entity, mut task, account) in query.iter_mut() {
191        if let Some(poll_res) = future::block_on(future::poll_once(&mut task.0)) {
192            let mut entity_mut = commands.entity(entity);
193            entity_mut.remove::<CreateConnectionTask>();
194            let conn = match poll_res {
195                Ok(conn) => conn,
196                Err(error) => {
197                    warn!("failed to create connection: {error}");
198                    connection_failed_events.write(ConnectionFailedEvent { entity, error });
199                    return;
200                }
201            };
202
203            let (read_conn, write_conn) = conn.into_split();
204            let (read_conn, write_conn) = (read_conn.raw, write_conn.raw);
205
206            let instance = Instance::default();
207            let instance_holder = crate::local_player::InstanceHolder::new(
208                entity,
209                // default to an empty world, it'll be set correctly later when we
210                // get the login packet
211                Arc::new(RwLock::new(instance)),
212            );
213
214            entity_mut.insert((
215                // these stay when we switch to the game state
216                LocalPlayerBundle {
217                    raw_connection: RawConnection::new(
218                        read_conn,
219                        write_conn,
220                        ConnectionProtocol::Login,
221                    ),
222                    instance_holder,
223                    metadata: azalea_entity::metadata::PlayerMetadataBundle::default(),
224                },
225                InLoginState,
226            ));
227
228            commands.trigger(SendLoginPacketEvent::new(
229                entity,
230                ServerboundHello {
231                    name: account.username.clone(),
232                    profile_id: account.uuid_or_offline(),
233                },
234            ));
235        }
236    }
237}
azalea_client/plugins/join.rs

azalea_client/plugins/
join.rs
