From dc5abd6f3b56c5dbc71aa8bb5dcfc667eb9abf0d Mon Sep 17 00:00:00 2001
From: Matthias Ahouansou <matthias@ahouansou.cz>
Date: Sat, 8 Mar 2025 11:26:17 +0000
Subject: [PATCH] feat(appservice): pinging

---
 src/api/client_server/appservice.rs | 80 +++++++++++++++++++++++++++++
 src/api/client_server/mod.rs        |  2 +
 src/main.rs                         |  1 +
 src/utils/error.rs                  |  2 +
 4 files changed, 85 insertions(+)
 create mode 100644 src/api/client_server/appservice.rs

diff --git a/src/api/client_server/appservice.rs b/src/api/client_server/appservice.rs
new file mode 100644
index 00000000..1b525f7c
--- /dev/null
+++ b/src/api/client_server/appservice.rs
@@ -0,0 +1,80 @@
+use std::time::Instant;
+
+use ruma::api::{
+    appservice::ping::send_ping,
+    client::{appservice::request_ping, error::ErrorKind},
+};
+
+use crate::{api::appservice_server, Error, Result, Ruma};
+
+/// # `POST /_matrix/client/v1/appservice/{appserviceId}/ping`
+///
+/// Allows an appservice to check whether the server and
+/// appservice can connect, and how fast their connection is
+pub async fn ping_appservice_route(
+    body: Ruma<request_ping::v1::Request>,
+) -> Result<request_ping::v1::Response> {
+    let Ruma::<request_ping::v1::Request> {
+        appservice_info,
+        body,
+        ..
+    } = body;
+
+    let registration = appservice_info
+        .expect("Only appservices can call this endpoint")
+        .registration;
+
+    if registration.id != body.appservice_id {
+        return Err(Error::BadRequest(
+            ErrorKind::forbidden(),
+            "Appservice ID specified in path does not match the requesting access token",
+        ));
+    }
+
+    if registration.url.is_some() {
+        let start = Instant::now();
+        let response = appservice_server::send_request(
+            registration,
+            send_ping::v1::Request {
+                transaction_id: body.transaction_id,
+            },
+        )
+        .await;
+        let elapsed = start.elapsed();
+
+        if let Err(error) = response {
+            Err(match error {
+                Error::ReqwestError { source } => {
+                    if source.is_timeout() {
+                        Error::BadRequest(
+                            ErrorKind::ConnectionTimeout,
+                            "Connection to appservice timed-out",
+                        )
+                    } else if let Some(status_code) = source.status() {
+                        Error::BadRequest(
+                            ErrorKind::BadStatus {
+                                status: Some(status_code),
+                                body: Some(source.to_string()),
+                            },
+                            "Ping returned error status",
+                        )
+                    } else {
+                        Error::BadRequest(ErrorKind::ConnectionFailed, "Failed to ping appservice")
+                    }
+                }
+                Error::BadServerResponse(_) => Error::BadRequest(
+                    ErrorKind::ConnectionFailed,
+                    "Recieved invalid response from appservice",
+                ),
+                e => e,
+            })
+        } else {
+            Ok(request_ping::v1::Response::new(elapsed))
+        }
+    } else {
+        Err(Error::BadRequest(
+            ErrorKind::UrlNotSet,
+            "Appservice doesn't have a URL configured",
+        ))
+    }
+}
diff --git a/src/api/client_server/mod.rs b/src/api/client_server/mod.rs
index a35d7a98..e5d0a5d5 100644
--- a/src/api/client_server/mod.rs
+++ b/src/api/client_server/mod.rs
@@ -1,5 +1,6 @@
 mod account;
 mod alias;
+mod appservice;
 mod backup;
 mod capabilities;
 mod config;
@@ -37,6 +38,7 @@ mod well_known;
 
 pub use account::*;
 pub use alias::*;
+pub use appservice::*;
 pub use backup::*;
 pub use capabilities::*;
 pub use config::*;
diff --git a/src/main.rs b/src/main.rs
index 5669cc0a..48d082cc 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -279,6 +279,7 @@ async fn unrecognized_method(
 
 fn routes(config: &Config) -> Router {
     let router = Router::new()
+        .ruma_route(client_server::ping_appservice_route)
         .ruma_route(client_server::get_supported_versions_route)
         .ruma_route(client_server::get_register_available_route)
         .ruma_route(client_server::register_route)
diff --git a/src/utils/error.rs b/src/utils/error.rs
index 50afd6d0..406db205 100644
--- a/src/utils/error.rs
+++ b/src/utils/error.rs
@@ -122,6 +122,8 @@ impl Error {
                     LimitExceeded { .. } => StatusCode::TOO_MANY_REQUESTS,
                     UserDeactivated => StatusCode::FORBIDDEN,
                     TooLarge => StatusCode::PAYLOAD_TOO_LARGE,
+                    ConnectionTimeout => StatusCode::GATEWAY_TIMEOUT,
+                    BadStatus { .. } | ConnectionFailed => StatusCode::BAD_GATEWAY,
                     _ => StatusCode::BAD_REQUEST,
                 },
             ),