Expose the SNI when possible. (#2943)

Grabs the SNI from TLS connections and saves to ConenctionMeta struct. Provides useful methods for exracting the SNI from requests.

Closes #2942

Author: hcldan

.editorconfig

@@ -0,0 +1,8 @@
+root = true
+
+[*.rs]
+insert_final_newline = true
+trim_trailing_whitespace = true
+indent_style = space
+indent_size = 4
+tab_width = 4

core/lib/src/listener/connection.rs

@@ -22,6 +22,8 @@ pub trait Connection: AsyncRead + AsyncWrite + Send + Unpin {
     /// Defaults to an empty vector to indicate that no certificates were
     /// presented.
     fn certificates(&self) -> Option<Certificates<'_>> { None }
+
+    fn server_name(&self) -> Option<&str> { None }
 }
 
 impl<A: Connection, B: Connection> Connection for Either<A, B> {

core/lib/src/request/request.rs

@@ -45,13 +45,19 @@ pub(crate) struct ConnectionMeta {
     pub peer_endpoint: Option<Endpoint>,
     #[cfg_attr(not(feature = "mtls"), allow(dead_code))]
     pub peer_certs: Option<Arc<Certificates<'static>>>,
+    #[cfg_attr(feature = "tls", allow(dead_code))]
+    pub server_name: Option<String>,
 }
 
 impl ConnectionMeta {
-    pub fn new(endpoint: io::Result<Endpoint>, certs: Option<Certificates<'_>>) -> Self {
+    pub fn new(
+        endpoint: io::Result<Endpoint>,
+        certs: Option<Certificates<'_>>,
+        server_name: Option<&str>) -> Self {
         ConnectionMeta {
             peer_endpoint: endpoint.ok(),
             peer_certs: certs.map(|c| c.into_owned()).map(Arc::new),
+            server_name: server_name.map(|s| s.to_string()),
         }
     }
 }
@@ -295,6 +301,16 @@ impl<'r> Request<'r> {
         self.state.host.as_ref()
     }
 
+    /// Returns the resolved SNI server name requested in the TLS handshake, if
+    /// any.
+    ///
+    /// Ideally, this will match the `Host` header in the request.
+    #[cfg(feature = "tls")]
+    #[inline(always)]
+    pub fn sni(&mut self) -> Option<&str> {
+        self.connection.server_name.as_deref()
+    }
+
     /// Sets the host of `self` to `host`.
     ///
     /// # Example

core/lib/src/server.rs

@@ -172,7 +172,11 @@ impl Rocket<Orbit> {
             let (listener, rocket, server) = (listener.clone(), self.clone(), server.clone());
             spawn_inspect(|e| log_server_error(&**e), async move {
                 let conn = listener.connect(accept).race_io(rocket.shutdown()).await?;
-                let meta = ConnectionMeta::new(conn.endpoint(), conn.certificates());
+                let meta = ConnectionMeta::new(
+                    conn.endpoint(),
+                    conn.certificates(),
+                    conn.server_name()
+                );
                 let service = service_fn(|mut req| {
                     let upgrade = hyper::upgrade::on(&mut req);
                     let (parts, incoming) = req.into_parts();
@@ -205,7 +209,7 @@ impl Rocket<Orbit> {
                 while let Some(mut conn) = stream.accept().race_io(rocket.shutdown()).await? {
                     let rocket = rocket.clone();
                     spawn_inspect(|e: &io::Error| log_server_error(e), async move {
-                        let meta = ConnectionMeta::new(conn.endpoint(), None);
+                        let meta = ConnectionMeta::new(conn.endpoint(), None, None);
                         let rx = conn.rx.cancellable(rocket.shutdown.clone());
                         let response = rocket.clone()
                             .service(conn.parts, rx, None, meta)

core/lib/src/tls/listener.rs

@@ -96,4 +96,13 @@ impl<C: Connection> Connection for TlsStream<C> {
         #[cfg(not(feature = "mtls"))]
         None
     }
+
+    fn server_name(&self) -> Option<&str> {
+        #[cfg(feature = "tls")] {
+            self.get_ref().1.server_name()
+        }
+
+        #[cfg(not(feature = "tls"))]
+        None
+    }
 }