Merge torrust#955: udp: processor for requests

019cf9f udp: processor for requests (Cameron Garnham)

Pull request description:

  Little work to cleanup the server udp launcher module.

ACKs for top commit:
  da2ce7:
    ACK 019cf9f

Tree-SHA512: fc32f73f7969d6c6b7f112306b2132cb853fbbe120979ea5826f835b570dff646fc73df66585a33c3223c85a3fd73373d9afcad6761ec5b67d7dca6a4688547d

Author: da2ce7

src/servers/udp/handlers.rs

@@ -33,7 +33,7 @@ use crate::shared::bit_torrent::common::MAX_SCRAPE_TORRENTS;
 /// - Delegating the request to the correct handler depending on the request type.
 ///
 /// It will return an `Error` response if the request is invalid.
-pub(crate) async fn handle_packet(udp_request: RawRequest, tracker: &Arc<Tracker>, addr: SocketAddr) -> Response {
+pub(crate) async fn handle_packet(udp_request: RawRequest, tracker: &Tracker, local_addr: SocketAddr) -> Response {
     debug!("Handling Packets: {udp_request:?}");
 
     let start_time = Instant::now();
@@ -47,7 +47,7 @@ pub(crate) async fn handle_packet(udp_request: RawRequest, tracker: &Arc<Tracker
         }
     }) {
         Ok(request) => {
-            log_request(&request, &request_id, &addr);
+            log_request(&request, &request_id, &local_addr);
 
             let transaction_id = match &request {
                 Request::Connect(connect_request) => connect_request.transaction_id,
@@ -62,7 +62,7 @@ pub(crate) async fn handle_packet(udp_request: RawRequest, tracker: &Arc<Tracker
 
             let latency = start_time.elapsed();
 
-            log_response(&response, &transaction_id, &request_id, &addr, latency);
+            log_response(&response, &transaction_id, &request_id, &local_addr, latency);
 
             response
         }

src/servers/udp/server/bound_socket.rs

@@ -1,15 +1,14 @@
 use std::fmt::Debug;
 use std::net::SocketAddr;
 use std::ops::Deref;
-use std::sync::Arc;
 
 use url::Url;
 
 use crate::servers::udp::UDP_TRACKER_LOG_TARGET;
 
 /// Wrapper for Tokio [`UdpSocket`][`tokio::net::UdpSocket`] that is bound to a particular socket.
 pub struct BoundSocket {
-    socket: Arc<tokio::net::UdpSocket>,
+    socket: tokio::net::UdpSocket,
 }
 
 impl BoundSocket {
@@ -30,9 +29,7 @@ impl BoundSocket {
         let local_addr = format!("udp://{addr}");
         tracing::debug!(target: UDP_TRACKER_LOG_TARGET, local_addr, "UdpSocket::new (bound)");
 
-        Ok(Self {
-            socket: Arc::new(socket),
-        })
+        Ok(Self { socket })
     }
 
     /// # Panics

src/servers/udp/server/launcher.rs

@@ -1,26 +1,23 @@
-use std::io::Cursor;
 use std::net::SocketAddr;
 use std::sync::Arc;
 use std::time::Duration;
 
-use aquatic_udp_protocol::Response;
 use derive_more::Constructor;
 use futures_util::StreamExt;
 use tokio::select;
 use tokio::sync::oneshot;
 
 use super::request_buffer::ActiveRequests;
-use super::RawRequest;
 use crate::bootstrap::jobs::Started;
 use crate::core::Tracker;
 use crate::servers::logging::STARTED_ON;
 use crate::servers::registar::ServiceHealthCheckJob;
 use crate::servers::signals::{shutdown_signal_with_message, Halted};
 use crate::servers::udp::server::bound_socket::BoundSocket;
+use crate::servers::udp::server::processor::Processor;
 use crate::servers::udp::server::receiver::Receiver;
-use crate::servers::udp::{handlers, UDP_TRACKER_LOG_TARGET};
+use crate::servers::udp::UDP_TRACKER_LOG_TARGET;
 use crate::shared::bit_torrent::tracker::udp::client::check;
-use crate::shared::bit_torrent::tracker::udp::MAX_PACKET_SIZE;
 
 /// A UDP server instance launcher.
 #[derive(Constructor)]
@@ -109,6 +106,8 @@ impl Launcher {
         let local_addr = format!("udp://{addr}");
 
         loop {
+            let processor = Processor::new(receiver.socket.clone(), tracker.clone());
+
             if let Some(req) = {
                 tracing::trace!(target: UDP_TRACKER_LOG_TARGET, local_addr, "Udp::run_udp_server (wait for request)");
                 receiver.next().await
@@ -138,9 +137,7 @@ impl Launcher {
                 // are only adding and removing tasks without given them the
                 // chance to finish. However, the buffer is yielding before
                 // aborting one tasks, giving it the chance to finish.
-                let abort_handle: tokio::task::AbortHandle =
-                    tokio::task::spawn(Launcher::process_request(req, tracker.clone(), receiver.bound_socket.clone()))
-                        .abort_handle();
+                let abort_handle: tokio::task::AbortHandle = tokio::task::spawn(processor.process_request(req)).abort_handle();
 
                 if abort_handle.is_finished() {
                     continue;
@@ -156,56 +153,4 @@ impl Launcher {
             }
         }
     }
-
-    async fn process_request(request: RawRequest, tracker: Arc<Tracker>, socket: Arc<BoundSocket>) {
-        tracing::trace!(target: UDP_TRACKER_LOG_TARGET, request = %request.from, "Udp::process_request (receiving)");
-        Self::process_valid_request(tracker, socket, request).await;
-    }
-
-    async fn process_valid_request(tracker: Arc<Tracker>, socket: Arc<BoundSocket>, udp_request: RawRequest) {
-        tracing::trace!(target: UDP_TRACKER_LOG_TARGET, "Udp::process_valid_request. Making Response to {udp_request:?}");
-        let from = udp_request.from;
-        let response = handlers::handle_packet(udp_request, &tracker.clone(), socket.address()).await;
-        Self::send_response(&socket.clone(), from, response).await;
-    }
-
-    async fn send_response(bound_socket: &Arc<BoundSocket>, to: SocketAddr, response: Response) {
-        let response_type = match &response {
-            Response::Connect(_) => "Connect".to_string(),
-            Response::AnnounceIpv4(_) => "AnnounceIpv4".to_string(),
-            Response::AnnounceIpv6(_) => "AnnounceIpv6".to_string(),
-            Response::Scrape(_) => "Scrape".to_string(),
-            Response::Error(e) => format!("Error: {e:?}"),
-        };
-
-        tracing::debug!(target: UDP_TRACKER_LOG_TARGET, target = ?to, response_type,  "Udp::send_response (sending)");
-
-        let buffer = vec![0u8; MAX_PACKET_SIZE];
-        let mut cursor = Cursor::new(buffer);
-
-        match response.write_bytes(&mut cursor) {
-            Ok(()) => {
-                #[allow(clippy::cast_possible_truncation)]
-                let position = cursor.position() as usize;
-                let inner = cursor.get_ref();
-
-                tracing::debug!(target: UDP_TRACKER_LOG_TARGET, ?to, bytes_count = &inner[..position].len(), "Udp::send_response (sending...)" );
-                tracing::trace!(target: UDP_TRACKER_LOG_TARGET, ?to, bytes_count = &inner[..position].len(), payload = ?&inner[..position], "Udp::send_response (sending...)");
-
-                Self::send_packet(bound_socket, &to, &inner[..position]).await;
-
-                tracing::trace!(target:UDP_TRACKER_LOG_TARGET, ?to, bytes_count = &inner[..position].len(), "Udp::send_response (sent)");
-            }
-            Err(e) => {
-                tracing::error!(target: UDP_TRACKER_LOG_TARGET, ?to, response_type, err = %e, "Udp::send_response (error)");
-            }
-        }
-    }
-
-    async fn send_packet(bound_socket: &Arc<BoundSocket>, remote_addr: &SocketAddr, payload: &[u8]) {
-        tracing::trace!(target: UDP_TRACKER_LOG_TARGET, to = %remote_addr, ?payload, "Udp::send_response (sending)");
-
-        // doesn't matter if it reaches or not
-        drop(bound_socket.send_to(payload, remote_addr).await);
-    }
 }

src/servers/udp/server/mod.rs

@@ -5,6 +5,7 @@ use super::RawRequest;
 
 pub mod bound_socket;
 pub mod launcher;
+pub mod processor;
 pub mod receiver;
 pub mod request_buffer;
 pub mod spawner;

src/servers/udp/server/processor.rs

@@ -0,0 +1,66 @@
+use std::io::Cursor;
+use std::net::SocketAddr;
+use std::sync::Arc;
+
+use aquatic_udp_protocol::Response;
+
+use super::bound_socket::BoundSocket;
+use crate::core::Tracker;
+use crate::servers::udp::{handlers, RawRequest, UDP_TRACKER_LOG_TARGET};
+
+pub struct Processor {
+    socket: Arc<BoundSocket>,
+    tracker: Arc<Tracker>,
+}
+
+impl Processor {
+    pub fn new(socket: Arc<BoundSocket>, tracker: Arc<Tracker>) -> Self {
+        Self { socket, tracker }
+    }
+
+    pub async fn process_request(self, request: RawRequest) {
+        tracing::trace!(target: UDP_TRACKER_LOG_TARGET, request = %request.from, "Udp::process_request (receiving)");
+
+        let from = request.from;
+        let response = handlers::handle_packet(request, &self.tracker, self.socket.address()).await;
+        self.send_response(from, response).await;
+    }
+
+    async fn send_response(self, to: SocketAddr, response: Response) {
+        let response_type = match &response {
+            Response::Connect(_) => "Connect".to_string(),
+            Response::AnnounceIpv4(_) => "AnnounceIpv4".to_string(),
+            Response::AnnounceIpv6(_) => "AnnounceIpv6".to_string(),
+            Response::Scrape(_) => "Scrape".to_string(),
+            Response::Error(e) => format!("Error: {e:?}"),
+        };
+
+        tracing::debug!(target: UDP_TRACKER_LOG_TARGET, target = ?to, response_type,  "Udp::send_response (sending)");
+
+        let mut writer = Cursor::new(Vec::with_capacity(200));
+
+        match response.write_bytes(&mut writer) {
+            Ok(()) => {
+                let bytes_count = writer.get_ref().len();
+                let payload = writer.get_ref();
+
+                tracing::debug!(target: UDP_TRACKER_LOG_TARGET, ?to, bytes_count, "Udp::send_response (sending...)" );
+                tracing::trace!(target: UDP_TRACKER_LOG_TARGET, ?to, bytes_count, ?payload, "Udp::send_response (sending...)");
+
+                self.send_packet(&to, payload).await;
+
+                tracing::trace!(target:UDP_TRACKER_LOG_TARGET, ?to, bytes_count, "Udp::send_response (sent)");
+            }
+            Err(e) => {
+                tracing::error!(target: UDP_TRACKER_LOG_TARGET, ?to, response_type, err = %e, "Udp::send_response (error)");
+            }
+        }
+    }
+
+    async fn send_packet(&self, remote_addr: &SocketAddr, payload: &[u8]) {
+        tracing::trace!(target: UDP_TRACKER_LOG_TARGET, to = %remote_addr, ?payload, "Udp::send_response (sending)");
+
+        // doesn't matter if it reaches or not
+        drop(self.socket.send_to(payload, remote_addr).await);
+    }
+}

src/servers/udp/server/receiver.rs

@@ -11,21 +11,21 @@ use super::RawRequest;
 use crate::shared::bit_torrent::tracker::udp::MAX_PACKET_SIZE;
 
 pub struct Receiver {
-    pub bound_socket: Arc<BoundSocket>,
+    pub socket: Arc<BoundSocket>,
     data: RefCell<[u8; MAX_PACKET_SIZE]>,
 }
 
 impl Receiver {
     #[must_use]
     pub fn new(bound_socket: Arc<BoundSocket>) -> Self {
         Receiver {
-            bound_socket,
+            socket: bound_socket,
             data: RefCell::new([0; MAX_PACKET_SIZE]),
         }
     }
 
     pub fn bound_socket_address(&self) -> SocketAddr {
-        self.bound_socket.address()
+        self.socket.address()
     }
 }
 
@@ -36,7 +36,7 @@ impl Stream for Receiver {
         let mut buf = *self.data.borrow_mut();
         let mut buf = tokio::io::ReadBuf::new(&mut buf);
 
-        let Poll::Ready(ready) = self.bound_socket.poll_recv_from(cx, &mut buf) else {
+        let Poll::Ready(ready) = self.socket.poll_recv_from(cx, &mut buf) else {
             return Poll::Pending;
         };
 

src/shared/bit_torrent/common.rs

@@ -1,7 +1,6 @@
 //! `BitTorrent` protocol primitive types
 //!
 //! [BEP 3. The `BitTorrent` Protocol Specification](https://www.bittorrent.org/beps/bep_0003.html)
-use serde::{Deserialize, Serialize};
 
 /// The maximum number of torrents that can be returned in an `scrape` response.
 ///
@@ -21,14 +20,3 @@ pub const MAX_SCRAPE_TORRENTS: u8 = 74;
 /// See function to [`generate`](crate::core::auth::generate) the
 /// [`ExpiringKeys`](crate::core::auth::ExpiringKey) for more information.
 pub const AUTH_KEY_LENGTH: usize = 32;
-
-#[repr(u32)]
-#[derive(Serialize, Deserialize, Debug, PartialEq, Eq, Clone)]
-enum Actions {
-    // todo: it seems this enum is not used anywhere. Values match the ones in
-    // aquatic_udp_protocol::request::Request::from_bytes.
-    Connect = 0,
-    Announce = 1,
-    Scrape = 2,
-    Error = 3,
-}