1 files changed, 100 insertions, 0 deletions
diff --git a/src/proxy.rs b/src/proxy.rs
new file mode 100644
index 0000000..65fc5a8
--- /dev/null
+++ b/src/proxy.rs
@@ -0,0 +1,100 @@
+use crate::ServiceError;
+use http_body_util::{combinators::BoxBody, BodyExt};
+use hyper::{
+    body::Incoming,
+    header::UPGRADE,
+    http::{
+        uri::{PathAndQuery, Scheme},
+        HeaderValue,
+    },
+    upgrade::OnUpgrade,
+    Request, Uri,
+};
+use log::{debug, error, warn};
+use std::net::SocketAddr;
+use tokio::net::TcpStream;
+
+pub async fn proxy_request(
+    mut req: Request<Incoming>,
+    addr: SocketAddr,
+    backend: &SocketAddr,
+) -> Result<hyper::Response<BoxBody<bytes::Bytes, ServiceError>>, ServiceError> {
+    let scheme_secure = req.uri().scheme() == Some(&Scheme::HTTPS);
+    *req.uri_mut() = Uri::builder()
+        .path_and_query(
+            req.uri()
+                .clone()
+                .path_and_query()
+                .cloned()
+                .unwrap_or(PathAndQuery::from_static("/")),
+        )
+        .build()
+        .unwrap();
+
+    req.headers_mut().insert(
+        "x-forwarded-for",
+        HeaderValue::from_str(&format!("{addr}")).unwrap(),
+    );
+    req.headers_mut().insert(
+        "x-forwarded-proto",
+        if scheme_secure {
+            HeaderValue::from_static("https")
+        } else {
+            HeaderValue::from_static("http")
+        },
+    );
+
+    let do_upgrade = req.headers().contains_key(UPGRADE);
+    let on_upgrade_downstream = req.extensions_mut().remove::<OnUpgrade>();
+
+    debug!("\tforwarding to {}", backend);
+    let mut resp = {
+        let client_stream = TcpStream::connect(backend)
+            .await
+            .map_err(|_| ServiceError::CantConnect)?;
+
+        let (mut sender, conn) = hyper::client::conn::http1::handshake(client_stream)
+            .await
+            .map_err(ServiceError::Hyper)?;
+        tokio::task::spawn(async move {
+            if let Err(err) = conn.await {
+                warn!("connection failed: {:?}", err);
+            }
+        });
+        sender
+            .send_request(req)
+            .await
+            .map_err(ServiceError::Hyper)?
+    };
+
+    resp.headers_mut()
+        .insert("server", HeaderValue::from_static("gnix"));
+
+    if do_upgrade {
+        let on_upgrade_upstream = resp.extensions_mut().remove::<OnUpgrade>();
+        tokio::task::spawn(async move {
+            debug!("about upgrading connection, sending empty response");
+            match (
+                on_upgrade_upstream.unwrap().await,
+                on_upgrade_downstream.unwrap().await,
+            ) {
+                (Ok(mut upgraded_upstream), Ok(mut upgraded_downstream)) => {
+                    debug!("upgrade successful");
+                    match tokio::io::copy_bidirectional(
+                        &mut upgraded_downstream,
+                        &mut upgraded_upstream,
+                    )
+                    .await
+                    {
+                        Ok((from_client, from_server)) => {
+                            debug!("proxy socket terminated: {from_server} sent, {from_client} received")
+                        }
+                        Err(e) => warn!("proxy socket error: {e}"),
+                    }
+                }
+                (a, b) => error!("upgrade error: upstream={a:?} downstream={b:?}"),
+            }
+        });
+    }
+    Ok(resp.map(|b| b.map_err(ServiceError::Hyper).boxed()))
+}