feat: Add Meowlnir invite interception support

Co-authored-by: Jade Ellis <jade@ellis.link>

src/service/sending/antispam.rs

@@ -0,0 +1,72 @@
+use std::{fmt::Debug, mem};
+
+use bytes::BytesMut;
+use conduwuit::{Err, Result, config::MeowlnirConfig, debug_error, err, utils, warn};
+use reqwest::Client;
+use ruma::api::{IncomingResponse, MatrixVersion, OutgoingRequest, SendAccessToken};
+
+/// Sends a request to an antispam service
+pub(crate) async fn send_meowlnir_request<T>(
+	client: &Client,
+	config: &MeowlnirConfig,
+	request: T,
+) -> Result<Option<T::IncomingResponse>>
+where
+	T: OutgoingRequest + Debug + Send,
+{
+	const VERSIONS: [MatrixVersion; 1] = [MatrixVersion::V1_15];
+	if config.secret.is_empty() {
+		return Ok(None);
+	}
+	let secret = config.secret.as_str();
+	let http_request = request
+		.try_into_http_request::<BytesMut>(
+			config.base_url.as_str(),
+			SendAccessToken::Always(secret),
+			&VERSIONS,
+		)?
+		.map(BytesMut::freeze);
+	let reqwest_request = reqwest::Request::try_from(http_request)?;
+
+	let mut response = client.execute(reqwest_request).await.map_err(|e| {
+		warn!("Could not send request to antispam: {e:?}");
+		e
+	})?;
+
+	// reqwest::Response -> http::Response conversion
+	let status = response.status();
+	let mut http_response_builder = http::Response::builder()
+		.status(status)
+		.version(response.version());
+	mem::swap(
+		response.headers_mut(),
+		http_response_builder
+			.headers_mut()
+			.expect("http::response::Builder is usable"),
+	);
+
+	let body = response.bytes().await?; // TODO: handle timeout
+
+	if !status.is_success() {
+		debug_error!("Antispam response bytes: {:?}", utils::string_from_bytes(&body));
+		return match status {
+			| http::StatusCode::FORBIDDEN =>
+				Err!(Request(Forbidden("Request was rejected by antispam service.",))),
+			| _ => Err!(BadServerResponse(warn!(
+				"Antispam returned unsuccessful HTTP response {status}",
+			))),
+		};
+	}
+
+	let response = T::IncomingResponse::try_from_http_response(
+		http_response_builder
+			.body(body)
+			.expect("reqwest body is valid http body"),
+	);
+
+	response.map(Some).map_err(|e| {
+		err!(BadServerResponse(warn!(
+			"Antispam returned invalid/malformed response bytes: {e}",
+		)))
+	})
+}

src/service/sending/mod.rs

@@ -1,3 +1,4 @@
+mod antispam;
 mod appservice;
 mod data;
 mod dest;
@@ -12,7 +13,9 @@ use std::{
 
 use async_trait::async_trait;
 use conduwuit::{
-	Result, Server, debug, debug_warn, err, error,
+	Result, Server,
+	config::MeowlnirConfig,
+	debug, debug_warn, err, error,
 	smallvec::SmallVec,
 	utils::{ReadyExt, TryReadyExt, available_parallelism, math::usize_from_u64_truncated},
 	warn,
@@ -334,6 +337,18 @@ impl Service {
 		appservice::send_request(client, registration, request).await
 	}
 
+	/// Sends a request to the chosen antispam configuration
+	pub async fn send_meowlnir_antispam_request<T>(
+		&self,
+		config: &MeowlnirConfig,
+		request: T,
+	) -> Result<Option<T::IncomingResponse>>
+	where
+		T: OutgoingRequest + Debug + Send,
+	{
+		antispam::send_meowlnir_request(&self.services.client.appservice, config, request).await
+	}
+
 	/// Clean up queued sending event data
 	///
 	/// Used after we remove an appservice registration or a user deletes a push