Add event emitting to server

Signed-off-by: trivernis <trivernis@protonmail.com>

src/crypto/mod.rs

@@ -26,6 +26,7 @@ pub struct CryptoStream {
 impl CryptoStream {
     /// Creates a new crypto stream from a given Tcp Stream and with a given secret
     pub fn new(inner: TcpStream, secret_box: crypto_box::ChaChaBox) -> VentedResult<Self> {
+        inner.set_nonblocking(false)?;
         let send_stream = Arc::new(Mutex::new(inner.try_clone()?));
         let recv_stream = Arc::new(Mutex::new(inner));
 
@@ -66,12 +67,12 @@ impl CryptoStream {
     /// Reads an event from the stream. Blocks until data is received
     pub fn read(&self) -> VentedResult<Event> {
         let mut stream = self.recv_stream.lock();
-        let mut length_raw = [0u8; 64];
+        let mut length_raw = [0u8; 8];
         stream.read_exact(&mut length_raw)?;
 
         let length = BigEndian::read_u64(&length_raw);
         let mut ciphertext = vec![0u8; length as usize];
-        stream.read_exact(&mut ciphertext)?;
+        stream.read(&mut ciphertext)?;
 
         let number = self.recv_count.fetch_add(1, Ordering::SeqCst);
         let nonce = generate_nonce(number);
@@ -91,7 +92,7 @@ impl CryptoStream {
 fn generate_nonce(number: usize) -> GenericArray<u8, U24> {
     let result = sha2::Sha256::digest(&number.to_be_bytes()).to_vec();
     let mut nonce = [0u8; 24];
-    nonce.copy_from_slice(&result);
+    nonce.copy_from_slice(&result[0..24]);
 
     nonce.into()
 }

src/result.rs

@@ -6,6 +6,8 @@ pub type VentedResult<T> = Result<T, VentedError>;
 #[derive(Debug)]
 pub enum VentedError {
     NameDecodingError,
+    NotReady,
+    NotAServer(String),
     IOError(io::Error),
     SerializeError(rmp_serde::encode::Error),
     DeserializeError(rmp_serde::decode::Error),
@@ -24,6 +26,8 @@ impl fmt::Display for VentedError {
             Self::CryptoError(e) => write!(f, "Cryptography Error: {}", e),
             Self::UnexpectedEvent(e) => write!(f, "Received unexpected event: {}", e),
             Self::UnknownNode(n) => write!(f, "Received connection from unknown node: {}", n),
+            Self::NotReady => write!(f, "The connection is still being established."),
+            Self::NotAServer(n) => write!(f, "The given node {} is not a server", n),
         }
     }
 }

src/server/data.rs

@@ -0,0 +1,24 @@
+use crate::crypto::CryptoStream;
+use crate::event_handler::EventHandler;
+use crypto_box::SecretKey;
+use parking_lot::Mutex;
+use scheduled_thread_pool::ScheduledThreadPool;
+use std::collections::HashMap;
+use std::sync::Arc;
+
+#[derive(Clone, Debug)]
+pub struct Node {
+    pub id: String,
+    pub address: Option<String>,
+}
+
+#[derive(Clone)]
+pub(crate) struct ServerConnectionContext {
+    pub is_server: bool,
+    pub secret_key: SecretKey,
+    pub own_node_id: String,
+    pub known_nodes: Arc<Mutex<Vec<Node>>>,
+    pub event_handler: Arc<Mutex<EventHandler>>,
+    pub connections: Arc<Mutex<HashMap<String, CryptoStream>>>,
+    pub listener_pool: Arc<Mutex<ScheduledThreadPool>>,
+}

src/server/mod.rs

@@ -8,111 +8,225 @@ use crate::crypto::CryptoStream;
 use crate::event::Event;
 use crate::event_handler::EventHandler;
 use crate::result::{VentedError, VentedResult};
+use crate::server::data::{Node, ServerConnectionContext};
 use crate::server::server_events::{
     NodeInformationPayload, CONNECT_EVENT, CONN_ACCEPT_EVENT, CONN_REJECT_EVENT,
 };
 use parking_lot::Mutex;
 use std::io::Write;
 use std::sync::Arc;
+use std::thread;
 
+pub mod data;
 pub(crate) mod server_events;
 
 /// The vented server that provides parallel handling of connections
 pub struct VentedServer {
     connections: Arc<Mutex<HashMap<String, CryptoStream>>>,
-    known_nodes: Arc<Mutex<Vec<String>>>,
+    known_nodes: Arc<Mutex<Vec<Node>>>,
-    listener_pool: ScheduledThreadPool,
+    listener_pool: Arc<Mutex<ScheduledThreadPool>>,
-    sender_pool: ScheduledThreadPool,
+    sender_pool: Arc<Mutex<ScheduledThreadPool>>,
     event_handler: Arc<Mutex<EventHandler>>,
     secret_key: SecretKey,
     node_id: String,
 }
 
 impl VentedServer {
-    pub fn new(node_id: String, nodes: Vec<String>, num_threads: usize) -> Self {
+    pub fn new(node_id: String, nodes: Vec<Node>, num_threads: usize) -> Self {
         let mut rng = rand::thread_rng();
         Self {
             node_id,
             event_handler: Arc::new(Mutex::new(EventHandler::new())),
-            listener_pool: ScheduledThreadPool::new(num_threads),
+            listener_pool: Arc::new(Mutex::new(ScheduledThreadPool::new(num_threads))),
-            sender_pool: ScheduledThreadPool::new(num_threads),
+            sender_pool: Arc::new(Mutex::new(ScheduledThreadPool::new(num_threads))),
             connections: Arc::new(Mutex::new(HashMap::new())),
             secret_key: SecretKey::generate(&mut rng),
             known_nodes: Arc::new(Mutex::new(nodes)),
         }
     }
 
-    /// Starts listening on the specified address (with port!)
+    /// Emits an event to the specified Node
-    pub fn listen(&mut self, address: &str) -> VentedResult<()> {
+    pub fn emit(&self, node_id: String, event: Event) -> VentedResult<()> {
-        let listener = TcpListener::bind(address)?;
+        let handler = self.connections.lock().get(&node_id).cloned();
-        for connection in listener.incoming() {
+
-            match connection {
+        if let Some(handler) = handler {
-                Ok(stream) => self.handle_connection(stream)?,
+            self.sender_pool.lock().execute(move || {
-                Err(e) => log::trace!("Failed to establish connection: {}", e),
+                handler.send(event).expect("Failed to send event");
+            });
+            Ok(())
+        } else {
+            if let Some(node) = self.known_nodes.lock().iter().find(|n| n.id == node_id) {
+                if let Some(address) = &node.address {
+                    let handler = self.connect(address.clone())?;
+                    self.sender_pool.lock().execute(move || {
+                        handler.send(event).expect("Failed to send event");
+                    });
+                    Ok(())
+                } else {
+                    Err(VentedError::NotAServer(node_id))
+                }
+            } else {
+                Err(VentedError::UnknownNode(node_id))
             }
         }
+    }
 
-        Ok(())
+    /// Adds a handler for the given event
+    pub fn on<F: 'static>(&mut self, event_name: &str, handler: F)
+    where
+        F: Fn(Event) -> Option<Event> + Send + Sync,
+    {
+        self.event_handler.lock().on(event_name, handler);
     }
 
-    /// Handles a single connection by first performing a key exchange and
+    /// Starts listening on the specified address (with port!)
-    /// then establishing an encrypted connection
+    pub fn listen(&mut self, address: String) {
-    fn handle_connection(&mut self, mut stream: TcpStream) -> VentedResult<()> {
+        let context = self.get_server_context();
-        let secret_key = self.secret_key.clone();
+
-        let self_public_key = secret_key.public_key();
+        thread::spawn(move || match TcpListener::bind(address) {
-        let connections = Arc::clone(&self.connections);
+            Ok(listener) => {
-        let own_node_id = self.node_id.clone();
+                for connection in listener.incoming() {
-        let known_nodes = Arc::clone(&self.known_nodes);
+                    match connection {
-        let event_handler = Arc::clone(&self.event_handler);
+                        Ok(stream) => {
-
+                            if let Err(e) = Self::handle_connection(context.clone(), stream) {
-        self.listener_pool.execute(move || {
+                                log::error!("Failed to handle connection: {}", e);
-            match VentedServer::perform_key_exchange(
+                            }
-                &mut stream,
-                &secret_key,
-                &self_public_key,
-                own_node_id,
-                known_nodes,
-            ) {
-                Ok((node_id, secret_box)) => {
-                    let stream = CryptoStream::new(stream, secret_box)
-                        .expect("Failed to create crypto stream");
-                    connections
-                        .lock()
-                        .insert(node_id, CryptoStream::clone(&stream));
-                    while let Ok(event) = stream.read() {
-                        if let Some(response) = event_handler.lock().handle_event(event) {
-                            stream.send(response).expect("Failed to send response");
                         }
+                        Err(e) => log::trace!("Failed to establish connection: {}", e),
                     }
                 }
-                Err(e) => log::error!("Failed to establish connection: {}", e),
+            }
+            Err(e) => log::error!("Failed to bind listener: {}", e),
+        });
+    }
+
+    /// Returns a copy of the servers metadata
+    fn get_server_context(&self) -> ServerConnectionContext {
+        ServerConnectionContext {
+            is_server: true,
+            own_node_id: self.node_id.clone(),
+            secret_key: self.secret_key.clone(),
+            known_nodes: Arc::clone(&self.known_nodes),
+            connections: Arc::clone(&self.connections),
+            event_handler: Arc::clone(&self.event_handler),
+            listener_pool: Arc::clone(&self.listener_pool),
+        }
+    }
+
+    /// Handles a single connection by first performing a key exchange and
+    /// then establishing an encrypted connection
+    fn handle_connection(params: ServerConnectionContext, stream: TcpStream) -> VentedResult<()> {
+        let pool = Arc::clone(&params.listener_pool);
+        let event_handler = Arc::clone(&params.event_handler);
+
+        pool.lock().execute(move || {
+            let stream = VentedServer::get_crypto_stream(params, stream).expect("Listener failed");
+            while let Ok(event) = stream.read() {
+                if let Some(response) = event_handler.lock().handle_event(event) {
+                    stream.send(response).expect("Failed to send response");
+                }
             }
         });
+
         Ok(())
     }
 
-    /// Emits an event to the specified Node
+    fn get_crypto_stream(
-    pub fn emit(&self, node_id: &str, event: Event) -> bool {
+        params: ServerConnectionContext,
-        let handler = self.connections.lock().get(node_id).cloned();
+        mut stream: TcpStream,
+    ) -> VentedResult<CryptoStream> {
+        let (node_id, secret_box) = VentedServer::perform_key_exchange(
+            params.is_server,
+            &mut stream,
+            &params.secret_key,
+            params.own_node_id,
+            params.known_nodes,
+        )?;
 
-        if let Some(handler) = handler {
+        let stream = CryptoStream::new(stream, secret_box)?;
-            self.sender_pool.execute(move || {
+        params
-                handler.send(event).expect("Failed to send event");
+            .connections
-            });
+            .lock()
-            true
+            .insert(node_id, CryptoStream::clone(&stream));
+
+        Ok(stream)
+    }
+
+    /// Connects to the given address as a tcp client
+    fn connect(&self, address: String) -> VentedResult<CryptoStream> {
+        let stream = TcpStream::connect(address)?;
+        let mut context = self.get_server_context();
+        context.is_server = false;
+
+        let stream = Self::get_crypto_stream(context, stream)?;
+        self.listener_pool.lock().execute({
+            let stream = CryptoStream::clone(&stream);
+            let event_handler = Arc::clone(&self.event_handler);
+            move || {
+                while let Ok(event) = stream.read() {
+                    if let Some(response) = event_handler.lock().handle_event(event) {
+                        stream.send(response).expect("Failed to send response");
+                    }
+                }
+            }
+        });
+
+        Ok(stream)
+    }
+
+    /// Performs a key exchange
+    fn perform_key_exchange(
+        is_server: bool,
+        stream: &mut TcpStream,
+        secret_key: &SecretKey,
+        own_node_id: String,
+        known_nodes: Arc<Mutex<Vec<Node>>>,
+    ) -> VentedResult<(String, ChaChaBox)> {
+        if is_server {
+            Self::perform_server_key_exchange(stream, secret_key, own_node_id, known_nodes)
         } else {
-            false
+            Self::perform_client_key_exchange(stream, secret_key, own_node_id)
         }
     }
 
+    /// Performs the client side DH key exchange
+    fn perform_client_key_exchange(
+        mut stream: &mut TcpStream,
+        secret_key: &SecretKey,
+        own_node_id: String,
+    ) -> VentedResult<(String, ChaChaBox)> {
+        stream.write(
+            &Event::with_payload(
+                CONNECT_EVENT.to_string(),
+                &NodeInformationPayload {
+                    public_key: secret_key.public_key().to_bytes(),
+                    node_id: own_node_id,
+                },
+            )
+            .as_bytes(),
+        )?;
+        stream.flush()?;
+        let event = Event::from_bytes(&mut stream)?;
+        if event.name != CONN_ACCEPT_EVENT {
+            return Err(VentedError::UnknownNode(event.name));
+        }
+        let NodeInformationPayload {
+            public_key,
+            node_id,
+        } = event.get_payload::<NodeInformationPayload>().unwrap();
+        let public_key = PublicKey::from(public_key);
+        let secret_box = ChaChaBox::new(&public_key, &secret_key);
+
+        Ok((node_id, secret_box))
+    }
+
     /// Performs a DH key exchange by using the crypto_box module and events
     /// On success it returns a secret box with the established secret and the node id of the client
-    fn perform_key_exchange(
+    fn perform_server_key_exchange(
         mut stream: &mut TcpStream,
         secret_key: &SecretKey,
-        self_public_key: &PublicKey,
         own_node_id: String,
-        known_nodes: Arc<Mutex<Vec<String>>>,
+        known_nodes: Arc<Mutex<Vec<Node>>>,
     ) -> VentedResult<(String, ChaChaBox)> {
         let event = Event::from_bytes(&mut stream)?;
         if event.name != CONNECT_EVENT {
@@ -124,8 +238,14 @@ impl VentedServer {
         } = event.get_payload::<NodeInformationPayload>().unwrap();
         let public_key = PublicKey::from(public_key);
 
-        if !known_nodes.lock().contains(&node_id) {
+        if known_nodes
+            .lock()
+            .iter()
+            .find(|n| n.id == node_id)
+            .is_none()
+        {
             stream.write(&Event::new(CONN_REJECT_EVENT.to_string()).as_bytes())?;
+            stream.flush()?;
             return Err(VentedError::UnknownNode(node_id));
         }
 
@@ -134,12 +254,13 @@ impl VentedServer {
             &Event::with_payload(
                 CONN_ACCEPT_EVENT.to_string(),
                 &NodeInformationPayload {
-                    public_key: self_public_key.to_bytes(),
+                    public_key: secret_key.public_key().to_bytes(),
                     node_id: own_node_id,
                 },
             )
             .as_bytes(),
         )?;
+        stream.flush()?;
 
         Ok((node_id, secret_box))
     }

tests/test_communication.rs

@@ -1 +1,57 @@
+use std::sync::atomic::{AtomicUsize, Ordering};
+use std::sync::Arc;
+use std::thread;
+use std::time::Duration;
+use vented::event::Event;
+use vented::server::data::Node;
+use vented::server::VentedServer;
 
+#[test]
+fn test_server_communication() {
+    let ping_count = Arc::new(AtomicUsize::new(0));
+    let pong_count = Arc::new(AtomicUsize::new(0));
+    let nodes = vec![
+        Node {
+            id: "A".to_string(),
+            address: Some("localhost:22222".to_string()),
+        },
+        Node {
+            id: "B".to_string(),
+            address: None,
+        },
+    ];
+    let mut server_a = VentedServer::new("A".to_string(), nodes.clone(), 2);
+    let mut server_b = VentedServer::new("B".to_string(), nodes, 2);
+    server_a.listen("localhost:22222".to_string());
+    thread::sleep(Duration::from_millis(10));
+
+    server_a.on("ping", {
+        let ping_count = Arc::clone(&ping_count);
+        move |_| {
+            ping_count.fetch_add(1, Ordering::Relaxed);
+
+            Some(Event::new("pong".to_string()))
+        }
+    });
+    server_b.on("pong", {
+        let pong_count = Arc::clone(&pong_count);
+        move |_| {
+            pong_count.fetch_add(1, Ordering::Relaxed);
+            None
+        }
+    });
+    for _ in 0..10 {
+        server_b
+            .emit("A".to_string(), Event::new("ping".to_string()))
+            .unwrap();
+    }
+    server_a
+        .emit("B".to_string(), Event::new("pong".to_string()))
+        .unwrap();
+
+    // wait one second to make sure the servers were able to process the events
+    thread::sleep(Duration::from_secs(1));
+
+    assert_eq!(ping_count.load(Ordering::Relaxed), 10);
+    assert_eq!(pong_count.load(Ordering::Relaxed), 11);
+}