From b4d988d366fbd0116b2ceac78e127f1ed0bcaf9b Mon Sep 17 00:00:00 2001
From: "John T. Wodder II" <git@varonathe.org>
Date: Wed, 31 Jan 2024 11:58:54 -0500
Subject: [PATCH] Add "Server" header to all responses

---
 Cargo.toml    |  2 +-
 src/consts.rs |  6 ++++++
 src/main.rs   | 14 +++++++++++---
 3 files changed, 18 insertions(+), 4 deletions(-)

diff --git a/Cargo.toml b/Cargo.toml
index 6acb913..74610ba 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -40,7 +40,7 @@ thiserror = "1.0.56"
 time = { version = "0.3.31", features = ["formatting", "macros", "parsing", "serde"] }
 tokio = { version = "1.35.1", features = ["macros", "net", "rt-multi-thread", "sync"] }
 tower = "0.4.13"
-tower-http = { version = "0.5.1", features = ["trace"] }
+tower-http = { version = "0.5.1", features = ["set-header", "trace"] }
 tracing-subscriber = "0.3.18"
 url = { version = "2.5.0", features = ["serde"] }
 xml-rs = "0.8.19"
diff --git a/src/consts.rs b/src/consts.rs
index 04e20a0..8d267c1 100644
--- a/src/consts.rs
+++ b/src/consts.rs
@@ -1,6 +1,8 @@
 use std::num::NonZeroUsize;
 use time::{format_description::FormatItem, macros::format_description};
 
+/// The value of the "User-Agent" header sent in requests to the Dandi Archive
+/// and S3
 pub(crate) static USER_AGENT: &str = concat!(
     env!("CARGO_PKG_NAME"),
     "/",
@@ -10,6 +12,10 @@ pub(crate) static USER_AGENT: &str = concat!(
     ")",
 );
 
+/// The value of the "Server" header returned in all responses from dandidav
+pub(crate) static SERVER_VALUE: &str =
+    concat!(env!("CARGO_PKG_NAME"), "/", env!("CARGO_PKG_VERSION"));
+
 pub(crate) static DEFAULT_API_URL: &str = "https://api.dandiarchive.org/api";
 
 // Case sensitive:
diff --git a/src/main.rs b/src/main.rs
index 3beb24b..bbc56a3 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -3,14 +3,18 @@ mod dandi;
 mod dav;
 mod paths;
 mod s3;
-use crate::consts::{CSS_CONTENT_TYPE, DEFAULT_API_URL};
+use crate::consts::{CSS_CONTENT_TYPE, DEFAULT_API_URL, SERVER_VALUE};
 use crate::dandi::Client;
 use crate::dav::{DandiDav, Templater};
 use anyhow::Context;
 use axum::{
     body::Body,
     extract::Request,
-    http::{header::CONTENT_TYPE, response::Response, Method},
+    http::{
+        header::{HeaderValue, CONTENT_TYPE, SERVER},
+        response::Response,
+        Method,
+    },
     middleware::{self, Next},
     routing::get,
     Router,
@@ -19,7 +23,7 @@ use clap::Parser;
 use std::net::IpAddr;
 use std::sync::Arc;
 use tower::service_fn;
-use tower_http::trace::TraceLayer;
+use tower_http::{set_header::response::SetResponseHeaderLayer, trace::TraceLayer};
 use tracing_subscriber::filter::LevelFilter;
 
 static STYLESHEET: &str = include_str!("dav/static/styles.css");
@@ -73,6 +77,10 @@ async fn main() -> anyhow::Result<()> {
             }),
         )
         .layer(middleware::from_fn(handle_head))
+        .layer(SetResponseHeaderLayer::if_not_present(
+            SERVER,
+            HeaderValue::from_static(SERVER_VALUE),
+        ))
         .layer(TraceLayer::new_for_http());
     let listener = tokio::net::TcpListener::bind((args.ip_addr, args.port))
         .await