Merge #185: Axum HTTP tracker: announce request in public mode

da638d6 docs(http): fix extractor docs (Jose Celano)
30918da refactor(http): [#184] move extractor to extractor mod (Jose Celano)
99dbbe4 refactor(http): [#184] extract announce service in Axum tracker (Jose Celano)
02e2516 feat(http): [#184] Axum extractor for peer IP (Jose Celano)
74ed592 feat(http): [#184] added optional params to announce req in Axum implementation (Jose Celano)
b1612f6 test(http): improve tests (Jose Celano)
3eb7475 feat(http): [#184] normal (non-compact) announce response in axum tracker (Jose Celano)
42bd313 feat: [#184] calculate remote client ip depending on whether the tracker is running on reverse proxy or not (Jose Celano)
8318057 feat: [#184] add dependency: axum-client-ip (Jose Celano)
f327dcf fix(http): [#184] bencoded error responses for announce request (Jose Celano)
d0c8eb0 refactor(http): reorganize mods (Jose Celano)
03024e2 refactor(http): extract function to get client IP on reverse proxy (Jose Celano)

Pull request description:

  It implements the `announce` request handler in the Axum HTTP tracker for `public` mode.

  - [x] Normal (non-compact) response with only mandatory params
  - [x] Optional params for `announce` request
  - [x] Return bencoded error when remote client IP cannot be obtained from the `X-Forwarded-For` header on reverse proxy mode. See commented tests.
  - [x] Refactor: extract service for handler body.

  Out of this PR scope:

  - [ ] Capture unexpected handler errors and convert them into bencoded generic HTTP tracker response errors. Moved to [parent issue](#160).
  - [ ] Compact response.

  **UPDATE**: 16/02/2023

Top commit has no ACKs.

Tree-SHA512: 76f77ed87f64ff6a488090e9013d92cbc516135a770206408a38bcba1c57ceb01154cd87b7169ed01ee12791c12d5e991ab59c4e53ba7c164a146292d6a94677

Cargo.toml

@@ -60,6 +60,7 @@ aquatic_udp_protocol = "0.2"
 uuid = { version = "1", features = ["v4"] }
 axum = "0.6.1"
 axum-server = { version = "0.4.4", features = ["tls-rustls"] }
+axum-client-ip = "0.4.0"
 
 
 [dev-dependencies]

src/http/axum_implementation/extractors/announce_request.rs

@@ -0,0 +1,45 @@
+use std::panic::Location;
+
+use axum::async_trait;
+use axum::extract::FromRequestParts;
+use axum::http::request::Parts;
+use axum::response::{IntoResponse, Response};
+
+use crate::http::axum_implementation::query::Query;
+use crate::http::axum_implementation::requests::announce::{Announce, ParseAnnounceQueryError};
+use crate::http::axum_implementation::responses;
+
+pub struct ExtractRequest(pub Announce);
+
+#[async_trait]
+impl<S> FromRequestParts<S> for ExtractRequest
+where
+    S: Send + Sync,
+{
+    type Rejection = Response;
+
+    async fn from_request_parts(parts: &mut Parts, _state: &S) -> Result<Self, Self::Rejection> {
+        let raw_query = parts.uri.query();
+
+        if raw_query.is_none() {
+            return Err(responses::error::Error::from(ParseAnnounceQueryError::MissingParams {
+                location: Location::caller(),
+            })
+            .into_response());
+        }
+
+        let query = raw_query.unwrap().parse::<Query>();
+
+        if let Err(error) = query {
+            return Err(responses::error::Error::from(error).into_response());
+        }
+
+        let announce_request = Announce::try_from(query.unwrap());
+
+        if let Err(error) = announce_request {
+            return Err(responses::error::Error::from(error).into_response());
+        }
+
+        Ok(ExtractRequest(announce_request.unwrap()))
+    }
+}

src/http/axum_implementation/extractors/mod.rs

@@ -0,0 +1,3 @@
+pub mod announce_request;
+pub mod peer_ip;
+pub mod remote_client_ip;

src/http/axum_implementation/extractors/peer_ip.rs

@@ -0,0 +1,52 @@
+use std::net::IpAddr;
+use std::panic::Location;
+
+use axum::response::{IntoResponse, Response};
+use thiserror::Error;
+
+use super::remote_client_ip::RemoteClientIp;
+use crate::http::axum_implementation::responses;
+
+#[derive(Error, Debug)]
+pub enum ResolutionError {
+    #[error("missing the right most X-Forwarded-For IP (mandatory on reverse proxy tracker configuration) in {location}")]
+    MissingRightMostXForwardedForIp { location: &'static Location<'static> },
+    #[error("cannot get the client IP from the connection info in {location}")]
+    MissingClientIp { location: &'static Location<'static> },
+}
+
+impl From<ResolutionError> for responses::error::Error {
+    fn from(err: ResolutionError) -> Self {
+        responses::error::Error {
+            failure_reason: format!("{err}"),
+        }
+    }
+}
+
+/// It resolves the peer IP.
+///
+/// # Errors
+///
+/// Will return an error if the peer IP cannot be obtained according to the configuration.
+/// For example, if the IP is extracted from an HTTP header which is missing in the request.
+pub fn assign_ip_address_to_peer(on_reverse_proxy: bool, remote_client_ip: &RemoteClientIp) -> Result<IpAddr, Response> {
+    if on_reverse_proxy {
+        if let Some(ip) = remote_client_ip.right_most_x_forwarded_for {
+            Ok(ip)
+        } else {
+            Err(
+                responses::error::Error::from(ResolutionError::MissingRightMostXForwardedForIp {
+                    location: Location::caller(),
+                })
+                .into_response(),
+            )
+        }
+    } else if let Some(ip) = remote_client_ip.connection_info_ip {
+        Ok(ip)
+    } else {
+        Err(responses::error::Error::from(ResolutionError::MissingClientIp {
+            location: Location::caller(),
+        })
+        .into_response())
+    }
+}

src/http/axum_implementation/extractors/remote_client_ip.rs

@@ -0,0 +1,51 @@
+use std::net::{IpAddr, SocketAddr};
+
+use axum::async_trait;
+use axum::extract::{ConnectInfo, FromRequestParts};
+use axum::http::request::Parts;
+use axum::response::Response;
+use axum_client_ip::RightmostXForwardedFor;
+use serde::{Deserialize, Serialize};
+
+/// Given this request chain:
+///
+/// client          <-> http proxy 1                 <-> http proxy 2                          <-> server
+/// ip: 126.0.0.1       ip: 126.0.0.2                    ip: 126.0.0.3                             ip: 126.0.0.4
+///                     X-Forwarded-For: 126.0.0.1       X-Forwarded-For: 126.0.0.1,126.0.0.2
+///
+/// This extractor extracts these values from the HTTP headers and connection info.
+///
+/// `right_most_x_forwarded_for` = 126.0.0.2
+/// `connection_info_ip`         = 126.0.0.3
+///
+/// More info about inner extractors :<https://github.com/imbolc/axum-client-ip>
+#[derive(Serialize, Deserialize, Debug, PartialEq, Eq, Clone)]
+pub struct RemoteClientIp {
+    pub right_most_x_forwarded_for: Option<IpAddr>,
+    pub connection_info_ip: Option<IpAddr>,
+}
+
+#[async_trait]
+impl<S> FromRequestParts<S> for RemoteClientIp
+where
+    S: Send + Sync,
+{
+    type Rejection = Response;
+
+    async fn from_request_parts(parts: &mut Parts, state: &S) -> Result<Self, Self::Rejection> {
+        let right_most_x_forwarded_for = match RightmostXForwardedFor::from_request_parts(parts, state).await {
+            Ok(right_most_x_forwarded_for) => Some(right_most_x_forwarded_for.0),
+            Err(_) => None,
+        };
+
+        let connection_info_ip = match ConnectInfo::<SocketAddr>::from_request_parts(parts, state).await {
+            Ok(connection_info_socket_addr) => Some(connection_info_socket_addr.0.ip()),
+            Err(_) => None,
+        };
+
+        Ok(RemoteClientIp {
+            right_most_x_forwarded_for,
+            connection_info_ip,
+        })
+    }
+}