Handle HTTP errors sensibly on GET

src/handler.rs

@@ -50,9 +50,16 @@ impl async_tftp::server::Handler for Handler {
         match resource {
             Resource::Http(url) => {
                 // TODO: Add headers describing client
-                let req = self.http.get(url).send().await.map_err(|err| Error::Msg(err.to_string()))?;
-                let size = req.content_length();
-                let stream = req.bytes_stream()
+                let resp = self.http.get(url).send().await.map_err(|err| Error::Msg(err.to_string()))?;
+                match resp.status() {
+                    StatusCode::OK => {},
+                    StatusCode::NOT_FOUND => return Err(Error::FileNotFound),
+                    StatusCode::UNAUTHORIZED => return Err(Error::PermissionDenied),
+                    x => return Err(Error::Msg(x.to_string()))
+                }
+
+                let size = resp.content_length();
+                let stream = resp.bytes_stream()
                     .map_err(|e| futures::io::Error::new(futures::io::ErrorKind::Other, e))
                     .into_async_read();