X-Git-Url: http://these/git/?a=blobdiff_plain;f=crates%2Futils%2Fsrc%2Frate_limit%2Fmod.rs;h=1bb6f1b5f4e1279f3642b8a6b2c246c4569626a2;hb=92568956353f21649ed9aff68b42699c9d036f30;hp=ed019255f8026262f6977080c5667c4ee867cfb1;hpb=93931958277714fd738a8dd8ab965c39b5016f63;p=lemmy.git

diff --git a/crates/utils/src/rate_limit/mod.rs b/crates/utils/src/rate_limit/mod.rs
index ed019255..1bb6f1b5 100644
--- a/crates/utils/src/rate_limit/mod.rs
+++ b/crates/utils/src/rate_limit/mod.rs
@@ -1,15 +1,20 @@
-use crate::{error::LemmyError, utils::get_ip, IpAddr};
-use actix_web::dev::{Service, ServiceRequest, ServiceResponse, Transform};
+use crate::error::{LemmyError, LemmyErrorType};
+use actix_web::dev::{ConnectionInfo, Service, ServiceRequest, ServiceResponse, Transform};
+use enum_map::enum_map;
 use futures::future::{ok, Ready};
-use rate_limiter::{RateLimitType, RateLimiter};
+use rate_limiter::{InstantSecs, RateLimitStorage, RateLimitType};
 use serde::{Deserialize, Serialize};
 use std::{
   future::Future,
+  net::{IpAddr, Ipv4Addr, SocketAddr},
   pin::Pin,
   rc::Rc,
+  str::FromStr,
   sync::{Arc, Mutex},
   task::{Context, Poll},
+  time::Duration,
 };
+use tokio::sync::{mpsc, mpsc::Sender, OnceCell};
 use typed_builder::TypedBuilder;
 
 pub mod rate_limiter;
@@ -55,65 +60,131 @@ pub struct RateLimitConfig {
 }
 
 #[derive(Debug, Clone)]
-pub struct RateLimit {
-  // it might be reasonable to use a std::sync::Mutex here, since we don't need to lock this
-  // across await points
-  pub rate_limiter: Arc<Mutex<RateLimiter>>,
+struct RateLimit {
+  pub rate_limiter: RateLimitStorage,
   pub rate_limit_config: RateLimitConfig,
 }
 
 #[derive(Debug, Clone)]
-pub struct RateLimited {
-  rate_limiter: Arc<Mutex<RateLimiter>>,
-  rate_limit_config: RateLimitConfig,
+pub struct RateLimitedGuard {
+  rate_limit: Arc<Mutex<RateLimit>>,
   type_: RateLimitType,
 }
 
-pub struct RateLimitedMiddleware<S> {
-  rate_limited: RateLimited,
-  service: Rc<S>,
+/// Single instance of rate limit config and buckets, which is shared across all threads.
+#[derive(Clone)]
+pub struct RateLimitCell {
+  tx: Sender<RateLimitConfig>,
+  rate_limit: Arc<Mutex<RateLimit>>,
 }
 
-impl RateLimit {
-  pub fn message(&self) -> RateLimited {
+impl RateLimitCell {
+  /// Initialize cell if it wasnt initialized yet. Otherwise returns the existing cell.
+  pub async fn new(rate_limit_config: RateLimitConfig) -> &'static Self {
+    static LOCAL_INSTANCE: OnceCell<RateLimitCell> = OnceCell::const_new();
+    LOCAL_INSTANCE
+      .get_or_init(|| async {
+        let (tx, mut rx) = mpsc::channel::<RateLimitConfig>(4);
+        let rate_limit = Arc::new(Mutex::new(RateLimit {
+          rate_limiter: Default::default(),
+          rate_limit_config,
+        }));
+        let rate_limit2 = rate_limit.clone();
+        tokio::spawn(async move {
+          while let Some(r) = rx.recv().await {
+            rate_limit2
+              .lock()
+              .expect("Failed to lock rate limit mutex for updating")
+              .rate_limit_config = r;
+          }
+        });
+        RateLimitCell { tx, rate_limit }
+      })
+      .await
+  }
+
+  /// Call this when the config was updated, to update all in-memory cells.
+  pub async fn send(&self, config: RateLimitConfig) -> Result<(), LemmyError> {
+    self.tx.send(config).await?;
+    Ok(())
+  }
+
+  /// Remove buckets older than the given duration
+  pub fn remove_older_than(&self, mut duration: Duration) {
+    let mut guard = self
+      .rate_limit
+      .lock()
+      .expect("Failed to lock rate limit mutex for reading");
+    let rate_limit = &guard.rate_limit_config;
+
+    // If any rate limit interval is greater than `duration`, then the largest interval is used instead. This preserves buckets that would not pass the rate limit check.
+    let max_interval_secs = enum_map! {
+      RateLimitType::Message => rate_limit.message_per_second,
+      RateLimitType::Post => rate_limit.post_per_second,
+      RateLimitType::Register => rate_limit.register_per_second,
+      RateLimitType::Image => rate_limit.image_per_second,
+      RateLimitType::Comment => rate_limit.comment_per_second,
+      RateLimitType::Search => rate_limit.search_per_second,
+    }
+    .into_values()
+    .max()
+    .and_then(|max| u64::try_from(max).ok())
+    .unwrap_or(0);
+
+    duration = std::cmp::max(duration, Duration::from_secs(max_interval_secs));
+
+    guard
+      .rate_limiter
+      .remove_older_than(duration, InstantSecs::now())
+  }
+
+  pub fn message(&self) -> RateLimitedGuard {
     self.kind(RateLimitType::Message)
   }
 
-  pub fn post(&self) -> RateLimited {
+  pub fn post(&self) -> RateLimitedGuard {
     self.kind(RateLimitType::Post)
   }
 
-  pub fn register(&self) -> RateLimited {
+  pub fn register(&self) -> RateLimitedGuard {
     self.kind(RateLimitType::Register)
   }
 
-  pub fn image(&self) -> RateLimited {
+  pub fn image(&self) -> RateLimitedGuard {
     self.kind(RateLimitType::Image)
   }
 
-  pub fn comment(&self) -> RateLimited {
+  pub fn comment(&self) -> RateLimitedGuard {
     self.kind(RateLimitType::Comment)
   }
 
-  pub fn search(&self) -> RateLimited {
+  pub fn search(&self) -> RateLimitedGuard {
     self.kind(RateLimitType::Search)
   }
 
-  fn kind(&self, type_: RateLimitType) -> RateLimited {
-    RateLimited {
-      rate_limiter: self.rate_limiter.clone(),
-      rate_limit_config: self.rate_limit_config.clone(),
+  fn kind(&self, type_: RateLimitType) -> RateLimitedGuard {
+    RateLimitedGuard {
+      rate_limit: self.rate_limit.clone(),
       type_,
     }
   }
 }
 
-impl RateLimited {
+pub struct RateLimitedMiddleware<S> {
+  rate_limited: RateLimitedGuard,
+  service: Rc<S>,
+}
+
+impl RateLimitedGuard {
   /// Returns true if the request passed the rate limit, false if it failed and should be rejected.
   pub fn check(self, ip_addr: IpAddr) -> bool {
     // Does not need to be blocking because the RwLock in settings never held across await points,
     // and the operation here locks only long enough to clone
-    let rate_limit = self.rate_limit_config;
+    let mut guard = self
+      .rate_limit
+      .lock()
+      .expect("Failed to lock rate limit mutex for reading");
+    let rate_limit = &guard.rate_limit_config;
 
     let (kind, interval) = match self.type_ {
       RateLimitType::Message => (rate_limit.message, rate_limit.message_per_second),
@@ -123,13 +194,13 @@ impl RateLimited {
       RateLimitType::Comment => (rate_limit.comment, rate_limit.comment_per_second),
       RateLimitType::Search => (rate_limit.search, rate_limit.search_per_second),
     };
-    let mut limiter = self.rate_limiter.lock().expect("mutex poison error");
+    let limiter = &mut guard.rate_limiter;
 
-    limiter.check_rate_limit_full(self.type_, &ip_addr, kind, interval)
+    limiter.check_rate_limit_full(self.type_, ip_addr, kind, interval, InstantSecs::now())
   }
 }
 
-impl<S> Transform<S, ServiceRequest> for RateLimited
+impl<S> Transform<S, ServiceRequest> for RateLimitedGuard
 where
   S: Service<ServiceRequest, Response = ServiceResponse, Error = actix_web::Error> + 'static,
   S::Future: 'static,
@@ -175,10 +246,49 @@ where
       } else {
         let (http_req, _) = req.into_parts();
         Ok(ServiceResponse::from_err(
-          LemmyError::from_message("rate_limit_error"),
+          LemmyError::from(LemmyErrorType::RateLimitError),
           http_req,
         ))
       }
     })
   }
 }
+
+fn get_ip(conn_info: &ConnectionInfo) -> IpAddr {
+  conn_info
+    .realip_remote_addr()
+    .and_then(parse_ip)
+    .unwrap_or(IpAddr::V4(Ipv4Addr::new(127, 0, 0, 1)))
+}
+
+fn parse_ip(addr: &str) -> Option<IpAddr> {
+  if let Some(s) = addr.strip_suffix(']') {
+    IpAddr::from_str(s.get(1..)?).ok()
+  } else if let Ok(ip) = IpAddr::from_str(addr) {
+    Some(ip)
+  } else if let Ok(socket) = SocketAddr::from_str(addr) {
+    Some(socket.ip())
+  } else {
+    None
+  }
+}
+
+#[cfg(test)]
+mod tests {
+  #![allow(clippy::unwrap_used)]
+  #![allow(clippy::indexing_slicing)]
+
+  #[test]
+  fn test_parse_ip() {
+    let ip_addrs = [
+      "1.2.3.4",
+      "1.2.3.4:8000",
+      "2001:db8::",
+      "[2001:db8::]",
+      "[2001:db8::]:8000",
+    ];
+    for addr in ip_addrs {
+      assert!(super::parse_ip(addr).is_some(), "failed to parse {addr}");
+    }
+  }
+}