feat(server): add Builder::auto_date_header(bool) to allow disabling Date headers

The default is enabled `true`. The method exists on both HTTP/1 and HTTP/2 builders.

Author: edwardwc

src/proto/h1/conn.rs

@@ -62,6 +62,8 @@ where
                 #[cfg(feature = "server")]
                 h1_header_read_timeout_running: false,
                 #[cfg(feature = "server")]
+                date_header: true,
+                #[cfg(feature = "server")]
                 timer: Time::Empty,
                 preserve_header_case: false,
                 #[cfg(feature = "ffi")]
@@ -564,6 +566,8 @@ where
                 keep_alive: self.state.wants_keep_alive(),
                 req_method: &mut self.state.method,
                 title_case_headers: self.state.title_case_headers,
+                #[cfg(feature = "server")]
+                date_header: self.state.date_header,
             },
             buf,
         ) {
@@ -859,6 +863,8 @@ struct State {
     #[cfg(feature = "server")]
     h1_header_read_timeout_running: bool,
     #[cfg(feature = "server")]
+    date_header: bool,
+    #[cfg(feature = "server")]
     timer: Time,
     preserve_header_case: bool,
     #[cfg(feature = "ffi")]

src/proto/h1/mod.rs

@@ -103,6 +103,8 @@ pub(crate) struct Encode<'a, T> {
     keep_alive: bool,
     req_method: &'a mut Option<Method>,
     title_case_headers: bool,
+    #[cfg(feature = "server")]
+    date_header: bool,
 }
 
 /// Extra flags that a request "wants", like expect-continue or upgrades.

src/proto/h1/role.rs

@@ -934,7 +934,8 @@ impl Server {
         }
 
         // cached date is much faster than formatting every request
-        if !wrote_date {
+        // don't force the write if disabled
+        if !wrote_date && msg.date_header {
             dst.reserve(date::DATE_VALUE_LENGTH + 8);
             header_name_writer.write_header_name_with_colon(dst, "date: ", header::DATE);
             date::extend(dst);
@@ -2503,6 +2504,7 @@ mod tests {
                 keep_alive: true,
                 req_method: &mut None,
                 title_case_headers: true,
+                date_header: true,
             },
             &mut vec,
         )
@@ -2534,6 +2536,7 @@ mod tests {
                 keep_alive: true,
                 req_method: &mut None,
                 title_case_headers: false,
+                date_header: true,
             },
             &mut vec,
         )
@@ -2568,6 +2571,7 @@ mod tests {
                 keep_alive: true,
                 req_method: &mut None,
                 title_case_headers: true,
+                date_header: true,
             },
             &mut vec,
         )
@@ -2592,6 +2596,7 @@ mod tests {
                 keep_alive: true,
                 req_method: &mut Some(Method::CONNECT),
                 title_case_headers: false,
+                date_header: true,
             },
             &mut vec,
         )
@@ -2621,6 +2626,7 @@ mod tests {
                 keep_alive: true,
                 req_method: &mut None,
                 title_case_headers: true,
+                date_header: true,
             },
             &mut vec,
         )
@@ -2655,6 +2661,7 @@ mod tests {
                 keep_alive: true,
                 req_method: &mut None,
                 title_case_headers: false,
+                date_header: true,
             },
             &mut vec,
         )
@@ -2689,17 +2696,54 @@ mod tests {
                 keep_alive: true,
                 req_method: &mut None,
                 title_case_headers: true,
+                date_header: true,
             },
             &mut vec,
         )
         .unwrap();
 
+        // this will also test that the date does exist
         let expected_response =
             b"HTTP/1.1 200 OK\r\nCONTENT-LENGTH: 10\r\nContent-Type: application/json\r\nDate: ";
 
         assert_eq!(&vec[..expected_response.len()], &expected_response[..]);
     }
 
+    #[test]
+    fn test_disabled_date_header() {
+        use crate::proto::BodyLength;
+        use http::header::{HeaderValue, CONTENT_LENGTH};
+
+        let mut head = MessageHead::default();
+        head.headers
+            .insert("content-length", HeaderValue::from_static("10"));
+        head.headers
+            .insert("content-type", HeaderValue::from_static("application/json"));
+
+        let mut orig_headers = HeaderCaseMap::default();
+        orig_headers.insert(CONTENT_LENGTH, "CONTENT-LENGTH".into());
+        head.extensions.insert(orig_headers);
+
+        let mut vec = Vec::new();
+        Server::encode(
+            Encode {
+                head: &mut head,
+                body: Some(BodyLength::Known(10)),
+                keep_alive: true,
+                req_method: &mut None,
+                title_case_headers: true,
+                date_header: false,
+            },
+            &mut vec,
+        )
+        .unwrap();
+
+        let expected_response =
+            b"HTTP/1.1 200 OK\r\nCONTENT-LENGTH: 10\r\nContent-Type: application/json\r\n\r\n";
+
+        assert_eq!(&vec, &expected_response);
+    }
+
     #[test]
     fn parse_header_htabs() {
         let mut bytes = BytesMut::from("HTTP/1.1 200 OK\r\nserver: hello\tworld\r\n\r\n");
@@ -3037,6 +3081,7 @@ mod tests {
                     keep_alive: true,
                     req_method: &mut Some(Method::GET),
                     title_case_headers: false,
+                    date_header: true,
                 },
                 &mut vec,
             )
@@ -3065,6 +3110,7 @@ mod tests {
                     keep_alive: true,
                     req_method: &mut Some(Method::GET),
                     title_case_headers: false,
+                    date_header: true,
                 },
                 &mut vec,
             )

src/proto/h2/server.rs

@@ -55,6 +55,7 @@ pub(crate) struct Config {
     pub(crate) keep_alive_timeout: Duration,
     pub(crate) max_send_buffer_size: usize,
     pub(crate) max_header_list_size: u32,
+    pub(crate) date_header: bool,
 }
 
 impl Default for Config {
@@ -72,6 +73,7 @@ impl Default for Config {
             keep_alive_timeout: Duration::from_secs(20),
             max_send_buffer_size: DEFAULT_MAX_SEND_BUF_SIZE,
             max_header_list_size: DEFAULT_SETTINGS_MAX_HEADER_LIST_SIZE,
+            date_header: true,
         }
     }
 }
@@ -86,6 +88,7 @@ pin_project! {
         timer: Time,
         service: S,
         state: State<T, B>,
+        date_header: bool,
     }
 }
 
@@ -108,6 +111,7 @@ where
     ping: Option<(ping::Recorder, ping::Ponger)>,
     conn: Connection<Compat<T>, SendBuf<B::Data>>,
     closing: Option<crate::Error>,
+    date_header: bool,
 }
 
 impl<T, S, B, E> Server<T, S, B, E>
@@ -167,6 +171,7 @@ where
                 hs: handshake,
             },
             service,
+            date_header: config.date_header,
         }
     }
 
@@ -219,6 +224,7 @@ where
                         ping,
                         conn,
                         closing: None,
+                        date_header: me.date_header,
                     })
                 }
                 State::Serving(ref mut srv) => {
@@ -302,7 +308,13 @@ where
                             req.extensions_mut().insert(Protocol::from_inner(protocol));
                         }
 
-                        let fut = H2Stream::new(service.call(req), connect_parts, respond);
+                        let fut = H2Stream::new(
+                            service.call(req),
+                            connect_parts,
+                            respond,
+                            self.date_header,
+                        );
+
                         exec.execute_h2stream(fut);
                     }
                     Some(Err(e)) => {
@@ -357,6 +369,7 @@ pin_project! {
         reply: SendResponse<SendBuf<B::Data>>,
         #[pin]
         state: H2StreamState<F, B>,
+        date_header: bool,
     }
 }
 
@@ -392,10 +405,12 @@ where
         fut: F,
         connect_parts: Option<ConnectParts>,
         respond: SendResponse<SendBuf<B::Data>>,
+        date_header: bool,
     ) -> H2Stream<F, B> {
         H2Stream {
             reply: respond,
             state: H2StreamState::Service { fut, connect_parts },
+            date_header,
         }
     }
 }
@@ -454,10 +469,12 @@ where
                     let mut res = ::http::Response::from_parts(head, ());
                     super::strip_connection_headers(res.headers_mut(), false);
 
-                    // set Date header if it isn't already set...
-                    res.headers_mut()
-                        .entry(::http::header::DATE)
-                        .or_insert_with(date::update_and_header_value);
+                    // set Date header if it isn't already set if instructed
+                    if *me.date_header {
+                        res.headers_mut()
+                            .entry(::http::header::DATE)
+                            .or_insert_with(date::update_and_header_value);
+                    }
 
                     if let Some(connect_parts) = connect_parts.take() {
                         if res.status().is_success() {

src/server/conn/http1.rs

@@ -79,6 +79,7 @@ pub struct Builder {
     h1_writev: Option<bool>,
     max_buf_size: Option<usize>,
     pipeline_flush: bool,
+    date_header: bool,
 }
 
 /// Deconstructed parts of a `Connection`.
@@ -246,6 +247,7 @@ impl Builder {
             h1_writev: None,
             max_buf_size: None,
             pipeline_flush: false,
+            date_header: true,
         }
     }
     /// Set whether HTTP/1 connections should support half-closures.
@@ -359,6 +361,16 @@ impl Builder {
         self
     }
 
+    /// Set whether the `date` header should be included in HTTP responses.
+    ///
+    /// Note that including the `date` header is recommended by RFC 7231.
+    ///
+    /// Default is true.
+    pub fn auto_date_header(&mut self, enabled: bool) -> &mut Self {
+        self.date_header = enabled;
+        self
+    }
+
     /// Aggregates flushes to better support pipelined responses.
     ///
     /// Experimental, may have bugs.

src/server/conn/http2.rs

@@ -277,6 +277,16 @@ impl<E> Builder<E> {
         self
     }
 
+    /// Set whether the `date` header should be included in HTTP responses.
+    ///
+    /// Note that including the `date` header is recommended by RFC 7231.
+    ///
+    /// Default is true.
+    pub fn auto_date_header(&mut self, enabled: bool) -> &mut Self {
+        self.h2_builder.date_header = enabled;
+        self
+    }
+
     /// Bind a connection together with a [`Service`](crate::service::Service).
     ///
     /// This returns a Future that must be polled in order for HTTP to be

tests/server.rs

@@ -2529,6 +2529,7 @@ async fn http2_keep_alive_detects_unresponsive_client() {
         .timer(TokioTimer)
         .keep_alive_interval(Duration::from_secs(1))
         .keep_alive_timeout(Duration::from_secs(1))
+        .auto_date_header(true)
         .serve_connection(socket, unreachable_service())
         .await
         .expect_err("serve_connection should error");
@@ -2569,6 +2570,42 @@ async fn http2_keep_alive_with_responsive_client() {
     client.send_request(req).await.expect("client.send_request");
 }
 
+#[tokio::test]
+async fn http2_check_date_header_disabled() {
+    let (listener, addr) = setup_tcp_listener();
+
+    tokio::spawn(async move {
+        let (socket, _) = listener.accept().await.expect("accept");
+        let socket = TokioIo::new(socket);
+
+        http2::Builder::new(TokioExecutor)
+            .timer(TokioTimer)
+            .keep_alive_interval(Duration::from_secs(1))
+            .auto_date_header(false)
+            .keep_alive_timeout(Duration::from_secs(1))
+            .serve_connection(socket, HelloWorld)
+            .await
+            .expect("serve_connection");
+    });
+
+    let tcp = TokioIo::new(connect_async(addr).await);
+    let (mut client, conn) = hyper::client::conn::http2::Builder::new(TokioExecutor)
+        .handshake(tcp)
+        .await
+        .expect("http handshake");
+
+    tokio::spawn(async move {
+        conn.await.expect("client conn");
+    });
+
+    TokioTimer.sleep(Duration::from_secs(4)).await;
+
+    let req = http::Request::new(Empty::<Bytes>::new());
+    let resp = client.send_request(req).await.expect("client.send_request");
+
+    assert!(resp.headers().get("Date").is_none());
+}
+
 fn is_ping_frame(buf: &[u8]) -> bool {
     buf[3] == 6
 }