Add proxy control

src/lib.rs

@@ -1,8 +1,12 @@
+use axum::extract::State;
 use axum::{http::StatusCode, Json};
 use serde::{Deserialize, Serialize};
-use std::net::{IpAddr, SocketAddr};
+use std::collections::HashMap;
+use std::net::{Ipv4Addr, SocketAddrV4};
+use std::sync::{Arc, Mutex};
 use tokio::io::{self, AsyncWriteExt};
 use tokio::net::{TcpListener, TcpStream};
+use tokio::sync::watch::{self, Receiver, Sender};
 use uuid::Uuid;
 
 #[derive(Deserialize, Serialize, Debug)]
@@ -16,11 +20,12 @@ enum Command {
     New {
         incoming_port: u16,
         destination_port: u16,
-        destination_ip: IpAddr,
+        destination_ip: Ipv4Addr,
         id: Uuid,
     },
     Modify {
-        destionation_ip: IpAddr,
+        destination_port: u16,
+        destination_ip: Ipv4Addr,
         id: Uuid,
     },
     Delete {
@@ -33,11 +38,31 @@ pub struct ProxyResponse {
     message: String,
 }
 
+#[derive(Debug)]
+pub struct GlobalState {
+    proxies: Mutex<HashMap<Uuid, ProxyState>>,
+}
+
+impl GlobalState {
+    pub fn new() -> Self {
+        Self {
+            proxies: Mutex::new(HashMap::new()),
+        }
+    }
+}
+
+#[derive(Debug)]
+struct ProxyState {
+    destination: SocketAddrV4,
+    control: Sender<ProxyControlMessage>,
+}
+
 pub async fn root() -> &'static str {
     "Hello, World!"
 }
 
 pub async fn process_command(
+    State(state): State<Arc<GlobalState>>,
     Json(payload): Json<ProxyCommand>,
 ) -> (StatusCode, Json<ProxyResponse>) {
     tracing::error!("Received payload: {:?}", payload);
@@ -49,19 +74,38 @@ pub async fn process_command(
             destination_ip,
             id,
         } => {
-            // TODO: add id to global proxy map
-            add_proxy(
-                incoming_port,
-                SocketAddr::new(destination_ip, destination_port),
-            )
-            .await
-            .unwrap(); // TODO: error propagation??
+            let addr = SocketAddrV4::new(destination_ip, destination_port);
+            let (tx, rx) = watch::channel(ProxyControlMessage::Open { destination: addr });
+            state.proxies.lock().unwrap().insert(
+                id,
+                ProxyState {
+                    destination: addr,
+                    control: tx,
+                },
+            );
+            add_proxy(incoming_port, rx).await.unwrap(); // TODO: error propagation??
         }
         Command::Modify {
-            destionation_ip,
+            destination_port,
+            destination_ip,
             id,
-        } => todo!(),
-        Command::Delete { id } => todo!(),
+        } => {
+            if let Some(proxy) = state.proxies.lock().unwrap().get_mut(&id) {
+                proxy.destination.set_port(destination_port);
+                proxy.destination.set_ip(destination_ip);
+                proxy
+                    .control
+                    .send(ProxyControlMessage::Open {
+                        destination: proxy.destination,
+                    })
+                    .unwrap();
+            }
+        }
+        Command::Delete { id } => {
+            if let Some(proxy) = state.proxies.lock().unwrap().get_mut(&id) {
+                proxy.control.send(ProxyControlMessage::Close).unwrap();
+            }
+        }
     }
     (
         StatusCode::CREATED,
@@ -71,24 +115,54 @@ pub async fn process_command(
     )
 }
 
-async fn add_proxy(in_port: u16, destination: SocketAddr) -> anyhow::Result<()> {
+#[derive(Debug)]
+enum ProxyControlMessage {
+    Open { destination: SocketAddrV4 }, // Reroute { new: SocketAddr },
+    Close,
+}
+
+async fn add_proxy(in_port: u16, control: Receiver<ProxyControlMessage>) -> anyhow::Result<()> {
     let listener = TcpListener::bind(("127.0.0.1", in_port)).await?;
 
-    tracing::info!("proxying port {in_port} to {destination}");
+    tracing::info!("proxying port {in_port} to {:?}", *control.borrow());
 
-    tokio::spawn(proxy(listener, destination));
+    tokio::spawn(proxy(listener, control));
     Ok(())
 }
 
-async fn proxy(listener: TcpListener, destination: SocketAddr) {
-    while let Ok((inbound, _)) = listener.accept().await {
-        let transfer = transfer(inbound, destination);
+async fn proxy(listener: TcpListener, mut control: Receiver<ProxyControlMessage>) {
+    let mut current_destination =
+        if let ProxyControlMessage::Open { destination } = *control.borrow() {
+            Some(destination)
+        } else {
+            None
+        };
+    loop {
+        tokio::select! {
+            l = listener.accept()=> {
+                if let Ok((inbound, _)) = l {
+                    let transfer = transfer(inbound, current_destination.unwrap());
 
-        tokio::spawn(transfer);
+                    tokio::spawn(transfer);
+                }
+            }
+            _ = control.changed() => {
+                match *control.borrow() {
+                    ProxyControlMessage::Open { destination } => {
+                        tracing::info!("destination for proxy port {} changed to {}", listener.local_addr().unwrap(), destination);
+                        current_destination=Some(destination);
+                    },
+                    ProxyControlMessage::Close => {
+                        tracing::info!("destination for proxy port {} closed", listener.local_addr().unwrap());
+                        return;
+                    },
+                }
+            }
+        }
     }
 }
 
-async fn transfer(mut inbound: TcpStream, destination: SocketAddr) -> anyhow::Result<()> {
+async fn transfer(mut inbound: TcpStream, destination: SocketAddrV4) -> anyhow::Result<()> {
     let mut outbound = TcpStream::connect(destination).await?;
 
     let (mut ri, mut wi) = inbound.split();
@@ -123,7 +197,7 @@ mod tests {
             command: Command::New {
                 incoming_port: 5555,
                 destination_port: 6666,
-                destination_ip: std::net::IpAddr::V4(Ipv4Addr::new(127, 0, 0, 1)),
+                destination_ip: Ipv4Addr::new(127, 0, 0, 1),
                 id: uuid!("67e55044-10b1-426f-9247-bb680e5fe0c8"),
             },
             signature: [0u8; 32],

src/main.rs

@@ -2,8 +2,8 @@ use axum::{
     routing::{get, post},
     Router,
 };
-use proxima_centauri::{process_command, root};
-use std::net::SocketAddr;
+use proxima_centauri::{process_command, root, GlobalState};
+use std::{net::SocketAddr, sync::Arc};
 use tracing::Level;
 
 #[tokio::main]
@@ -15,12 +15,14 @@ async fn main() {
 
     tracing::subscriber::set_global_default(subscriber).unwrap();
 
+    let shared_state = Arc::new(GlobalState::new());
     // build our application with a route
     let app = Router::new()
         // `GET /` goes to `root`
         .route("/", get(root))
         // `POST /command` goes to `process_command`
-        .route("/command", post(process_command));
+        .route("/command", post(process_command))
+        .with_state(shared_state);
 
     // run our app with hyper
     let addr = SocketAddr::from(([127, 0, 0, 1], 3000));