refactor: [torrust#1096] count bad UDP request where the error is captured

Instead of captured the mapped error in the caller function when the
error is already converted into a UDP error reponse.

This prevents from parsing the error message to filter the error we are
interesting in.

Author: josecelano

src/servers/udp/handlers.rs

@@ -11,6 +11,8 @@ use aquatic_udp_protocol::{
     ResponsePeer, ScrapeRequest, ScrapeResponse, TorrentScrapeStatistics, TransactionId,
 };
 use bittorrent_primitives::info_hash::InfoHash;
+use bloom::{CountingBloomFilter, ASMS};
+use tokio::sync::RwLock;
 use torrust_tracker_clock::clock::Time as _;
 use tracing::{instrument, Level};
 use uuid::Uuid;
@@ -51,12 +53,13 @@ impl CookieTimeValues {
 /// - Delegating the request to the correct handler depending on the request type.
 ///
 /// It will return an `Error` response if the request is invalid.
-#[instrument(fields(request_id), skip(udp_request, tracker, cookie_time_values), ret(level = Level::TRACE))]
+#[instrument(fields(request_id), skip(udp_request, tracker, cookie_time_values, cbf), ret(level = Level::TRACE))]
 pub(crate) async fn handle_packet(
     udp_request: RawRequest,
     tracker: &Tracker,
     local_addr: SocketAddr,
     cookie_time_values: CookieTimeValues,
+    cbf: Arc<RwLock<CountingBloomFilter>>,
 ) -> Response {
     tracing::Span::current().record("request_id", Uuid::new_v4().to_string());
     tracing::debug!("Handling Packets: {udp_request:?}");
@@ -68,6 +71,16 @@ pub(crate) async fn handle_packet(
             Ok(request) => match handle_request(request, udp_request.from, tracker, cookie_time_values.clone()).await {
                 Ok(response) => return response,
                 Err((e, transaction_id)) => {
+                    match &e {
+                        Error::CookieValueNotNormal { .. }
+                        | Error::CookieValueExpired { .. }
+                        | Error::CookieValueFromFuture { .. } => {
+                            // code-review: should we include `RequestParseError` and `BadRequest`?
+                            cbf.write().await.insert(&udp_request.from.ip().to_string());
+                        }
+                        _ => {}
+                    }
+
                     handle_error(
                         udp_request.from,
                         tracker,

src/servers/udp/server/processor.rs

@@ -3,7 +3,7 @@ use std::net::SocketAddr;
 use std::sync::Arc;
 
 use aquatic_udp_protocol::Response;
-use bloom::{CountingBloomFilter, ASMS};
+use bloom::CountingBloomFilter;
 use tokio::sync::RwLock;
 use tracing::{instrument, Level};
 
@@ -35,15 +35,10 @@ impl Processor {
             &self.tracker,
             self.socket.address(),
             CookieTimeValues::new(self.cookie_lifetime),
+            cbf,
         )
         .await;
 
-        if let Response::Error(err) = &response {
-            if err.message.contains("cookie value is expired") || err.message.contains("cookie value is from future") {
-                cbf.write().await.insert(&from.ip().to_string());
-            }
-        }
-
         self.send_response(from, response).await;
     }