fix: Report 413 instead of 500 if request too large. #977

h2oai · Aug 25, 2021 · 006e282 · 006e282
1 parent 304784b
commit 006e282
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Showing 4 changed files with 23 additions and 0 deletions.
diff --git a/cache.go b/cache.go
@@ -71,6 +71,10 @@ func (c *Cache) ServeHTTP(w http.ResponseWriter, r *http.Request) {
 		v, err := readRequestWithLimit(w, r.Body, c.maxRequestSize)
 		if err != nil {
 			echo(Log{"t": "read cache request body", "error": err.Error()})
+			if isRequestTooLarge(err) {
+				http.Error(w, http.StatusText(http.StatusRequestEntityTooLarge), http.StatusRequestEntityTooLarge)
+				return
+			}
 			http.Error(w, http.StatusText(http.StatusInternalServerError), http.StatusInternalServerError)
 			return
 		}

diff --git a/proxy.go b/proxy.go
@@ -77,6 +77,10 @@ func (p *Proxy) ServeHTTP(w http.ResponseWriter, r *http.Request) {
 		req, err := readRequestWithLimit(w, r.Body, p.maxRequestSize)
 		if err != nil {
 			echo(Log{"t": "read proxy request body", "error": err.Error()})
+			if isRequestTooLarge(err) {
+				http.Error(w, http.StatusText(http.StatusRequestEntityTooLarge), http.StatusRequestEntityTooLarge)
+				return
+			}
 			http.Error(w, http.StatusText(http.StatusInternalServerError), http.StatusInternalServerError)
 			return
 		}

diff --git a/server.go b/server.go
@@ -114,6 +114,13 @@ func readRequestWithLimit(w http.ResponseWriter, r io.ReadCloser, n int64) ([]by
 	return ioutil.ReadAll(http.MaxBytesReader(w, r, n))
 }
 
+func isRequestTooLarge(err error) bool {
+	// HACK: net/http does not export the error
+	// https://github.com/golang/go/issues/30715
+	// https://github.com/golang/go/issues/41493
+	return err != nil && err.Error() == "http: request body too large"
+}
+
 func readWithLimit(r io.Reader, n int64) ([]byte, error) {
 	return ioutil.ReadAll(io.LimitReader(r, n))
 }
diff --git a/web_server.go b/web_server.go
@@ -82,6 +82,10 @@ func (s *WebServer) patch(w http.ResponseWriter, r *http.Request) {
 	data, err := readRequestWithLimit(w, r.Body, s.maxRequestSize)
 	if err != nil {
 		echo(Log{"t": "read patch request body", "error": err.Error()})
+		if isRequestTooLarge(err) {
+			http.Error(w, http.StatusText(http.StatusRequestEntityTooLarge), http.StatusRequestEntityTooLarge)
+			return
+		}
 		http.Error(w, http.StatusText(http.StatusInternalServerError), http.StatusInternalServerError)
 		return
 	}
@@ -115,6 +119,10 @@ func (s *WebServer) post(w http.ResponseWriter, r *http.Request) {
 		b, err := readRequestWithLimit(w, r.Body, s.maxRequestSize)
 		if err != nil {
 			echo(Log{"t": "read post request body", "error": err.Error()})
+			if isRequestTooLarge(err) {
+				http.Error(w, http.StatusText(http.StatusRequestEntityTooLarge), http.StatusRequestEntityTooLarge)
+				return
+			}
 			http.Error(w, http.StatusText(http.StatusInternalServerError), http.StatusInternalServerError)
 			return
 		}