refactor: move ratelimits to a generic system for all web servers

2025-09-16 19:15:34 +01:00
parent 3a3415915f
commit fb4011084d
16 changed files with 705 additions and 358 deletions
--- a/crates/core/ratelimits/src/axum.rs
+++ b/crates/core/ratelimits/src/axum.rs
@@ -0,0 +1,193 @@
+use std::net::SocketAddr;
+
+use async_trait::async_trait;
+use axum::{
+    Json, RequestPartsExt, Router,
+    body::Body,
+    extract::{ConnectInfo, FromRef, FromRequestParts, State},
+    http::{HeaderValue, Request, StatusCode, request::Parts},
+    middleware::Next,
+    response::{IntoResponse, Response},
+    routing::get,
+};
+use revolt_database::{Database, User};
+
+use crate::ratelimiter::{RatelimitInformation, Ratelimiter, RequestKind};
+
+#[derive(Clone, Copy)]
+pub struct AxumRequestKind;
+
+impl RequestKind for AxumRequestKind {
+    type R<'a> = Parts;
+}
+
+pub type RatelimitStorage = crate::ratelimiter::RatelimitStorage<AxumRequestKind>;
+
+fn to_ip(parts: &Parts) -> String {
+    parts
+        .extensions
+        .get::<ConnectInfo<SocketAddr>>()
+        .map(|info| info.ip().to_string())
+        .unwrap_or_default()
+}
+
+fn to_real_ip(parts: &Parts) -> String {
+    if let Ok(true) = std::env::var("TRUST_CLOUDFLARE").map(|x| x == "1") {
+        parts
+            .headers
+            .get("CF-Connecting-IP")
+            .map(|x| x.to_str().unwrap().to_string())
+            .unwrap_or_else(|| to_ip(parts))
+    } else {
+        to_ip(parts)
+    }
+}
+
+#[async_trait]
+impl<S: Send + Sync> FromRequestParts<S> for Ratelimiter
+where
+    Database: FromRef<S>,
+    RatelimitStorage: FromRef<S>,
+{
+    type Rejection = Json<Ratelimiter>;
+
+    async fn from_request_parts(parts: &mut Parts, state: &S) -> Result<Self, Self::Rejection> {
+        if parts
+            .extensions
+            .get::<Result<Ratelimiter, Json<Ratelimiter>>>()
+            .is_none()
+        {
+            let storage = RatelimitStorage::from_ref(state);
+
+            let identifier = if let Ok(user) = parts.extract_with_state::<User, _>(state).await {
+                user.id
+            } else {
+                to_real_ip(parts)
+            };
+
+            let (bucket, resource) = storage.resolver.resolve_bucket(parts);
+            let limit = storage.resolver.resolve_bucket_limit(bucket);
+
+            let ratelimiter =
+                Ratelimiter::from(&storage.map, &identifier, limit, (bucket, resource));
+
+            parts.extensions.insert(ratelimiter.map_err(Json));
+        };
+
+        *parts
+            .extensions
+            .get::<Result<Ratelimiter, Json<Ratelimiter>>>()
+            .unwrap()
+    }
+}
+
+#[async_trait]
+impl<S: Send + Sync> FromRequestParts<S> for RatelimitInformation
+where
+    Database: FromRef<S>,
+    RatelimitStorage: FromRef<S>,
+{
+    type Rejection = Json<RatelimitInformation>;
+
+    async fn from_request_parts(parts: &mut Parts, state: &S) -> Result<Self, Self::Rejection> {
+        if parts
+            .extensions
+            .get::<Result<Ratelimiter, Json<Ratelimiter>>>()
+            .is_none()
+        {
+            let ratelimiter = parts.extract_with_state::<Ratelimiter, S>(state).await;
+
+            parts.extensions.insert(ratelimiter);
+        };
+
+        let ratelimiter = *parts
+            .extensions
+            .get::<Result<Ratelimiter, Json<Ratelimiter>>>()
+            .unwrap();
+
+        match ratelimiter {
+            Ok(ratelimter) => Ok(RatelimitInformation::Success(ratelimter)),
+            Err(ratelimiter) => Err(Json(RatelimitInformation::Failure {
+                retry_after: ratelimiter.reset,
+            })),
+        }
+    }
+}
+
+pub async fn ratelimit_middleware(
+    State(database): State<Database>,
+    State(ratelimit_storage): State<RatelimitStorage>,
+    request: Request<Body>,
+    next: Next,
+) -> Response {
+    #[derive(axum::extract::FromRef)]
+    struct TempState {
+        database: Database,
+        ratelimit_storage: RatelimitStorage,
+    }
+
+    let state = TempState {
+        database,
+        ratelimit_storage,
+    };
+
+    let (mut parts, body) = request.into_parts();
+
+    let res = Ratelimiter::from_request_parts(&mut parts, &state).await;
+
+    let (Ok(ratelimiter) | Err(Json(ratelimiter))) = &res;
+
+    let mut response = if res.is_ok() {
+        let request = Request::from_parts(parts, body);
+
+        next.run(request).await
+    } else {
+        let ratelimit_info = RatelimitInformation::from_request_parts(&mut parts, &state).await;
+
+        ratelimit_info.map(Json).into_response()
+    };
+
+    let Ratelimiter {
+        key,
+        limit,
+        remaining,
+        reset,
+    } = ratelimiter;
+
+    let headers = response.headers_mut();
+
+    headers.insert(
+        "X-RateLimit-Limit",
+        HeaderValue::from_str(&limit.to_string()).unwrap(),
+    );
+    headers.insert(
+        "X-RateLimit-Bucket",
+        HeaderValue::from_str(&key.to_string()).unwrap(),
+    );
+    headers.insert(
+        "X-RateLimit-Remaining",
+        HeaderValue::from_str(&remaining.to_string()).unwrap(),
+    );
+    headers.insert(
+        "X-RateLimit-Reset-After",
+        HeaderValue::from_str(&reset.to_string()).unwrap(),
+    );
+
+    if res.is_err() {
+        *response.status_mut() = StatusCode::TOO_MANY_REQUESTS;
+    };
+
+    response
+}
+
+async fn ratelimit_info(info: RatelimitInformation) -> Json<RatelimitInformation> {
+    Json(info)
+}
+
+pub fn routes<S: Clone + Send + Sync + 'static>() -> Router<S>
+where
+    Database: FromRef<S>,
+    RatelimitStorage: FromRef<S>,
+{
+    Router::new().route("/ratelimit", get(ratelimit_info))
+}