Fast and extensible multi-platform HTTP/1-2-3 web server with automatic HTTPS
Mirrored from https://github.com/Slazee/caddy.git
Synced Nov 12, 13:15 UTC
fileserver: Improve Vary handling (#5849)
Matthew Holt committed
Apr 19, 2024 at 13:43 UTC
d00824f4a648238cadacd1c999cedcba5f40323e
3 files changed
+30
-10
modules/caddyhttp/encode/encode.go
+23
-8
@@ -239,7 +239,7 @@ func (rw *responseWriter) WriteHeader(status int) {
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// Not Modified must have certain headers set as if it was a 200 response, and according to the issue
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// we would miss the Vary header in this case when compression was also enabled; note that we set this
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// header in the responseWriter.init() method but that is only called if we are writing a response body
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- if status == http.StatusNotModified {
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+ if status == http.StatusNotModified && !hasVaryValue(rw.Header(), "Accept-Encoding") {
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rw.Header().Add("Vary", "Accept-Encoding")
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}
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@@ -349,14 +349,17 @@ func (rw *responseWriter) Unwrap() http.ResponseWriter {
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// init should be called before we write a response, if rw.buf has contents.
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func (rw *responseWriter) init() {
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- if rw.Header().Get("Content-Encoding") == "" && isEncodeAllowed(rw.Header()) &&
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+ hdr := rw.Header()
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+ if hdr.Get("Content-Encoding") == "" && isEncodeAllowed(hdr) &&
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rw.config.Match(rw) {
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rw.w = rw.config.writerPools[rw.encodingName].Get().(Encoder)
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rw.w.Reset(rw.ResponseWriter)
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- rw.Header().Del("Content-Length") // https://github.com/golang/go/issues/14975
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- rw.Header().Set("Content-Encoding", rw.encodingName)
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- rw.Header().Add("Vary", "Accept-Encoding")
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- rw.Header().Del("Accept-Ranges") // we don't know ranges for dynamically-encoded content
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+ hdr.Del("Content-Length") // https://github.com/golang/go/issues/14975
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+ hdr.Set("Content-Encoding", rw.encodingName)
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+ if !hasVaryValue(hdr, "Accept-Encoding") {
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+ hdr.Add("Vary", "Accept-Encoding")
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+ }
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+ hdr.Del("Accept-Ranges") // we don't know ranges for dynamically-encoded content
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// strong ETags need to be distinct depending on the encoding ("selected representation")
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// see RFC 9110 section 8.8.3.3:
@@ -365,11 +368,23 @@ func (rw *responseWriter) init() {
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// (We have to strip the value we append from If-None-Match headers before
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// sending subsequent requests back upstream, however, since upstream handlers
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// don't know about our appending to their Etag since they've already done their work)
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- if etag := rw.Header().Get("Etag"); etag != "" && !strings.HasPrefix(etag, "W/") {
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+ if etag := hdr.Get("Etag"); etag != "" && !strings.HasPrefix(etag, "W/") {
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etag = fmt.Sprintf(`%s-%s"`, strings.TrimSuffix(etag, `"`), rw.encodingName)
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- rw.Header().Set("Etag", etag)
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+ hdr.Set("Etag", etag)
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+ }
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+ }
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+}
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+
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+func hasVaryValue(hdr http.Header, target string) bool {
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+ for _, vary := range hdr.Values("Vary") {
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+ vals := strings.Split(vary, ",")
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+ for _, val := range vals {
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+ if strings.EqualFold(strings.TrimSpace(val), target) {
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+ return true
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+ }
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}
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}
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+ return false
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}
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// AcceptedEncodings returns the list of encodings that the
modules/caddyhttp/fileserver/browse.go
+1
-1
@@ -105,7 +105,7 @@ func (fsrv *FileServer) serveBrowse(fileSystem fs.FS, root, dirPath string, w ht
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return caddyhttp.Error(http.StatusInternalServerError, err)
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}
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- w.Header().Add("Vary", "Accept")
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+ w.Header().Add("Vary", "Accept, Accept-Encoding")
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// speed up browser/client experience and caching by supporting If-Modified-Since
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if ifModSinceStr := r.Header.Get("If-Modified-Since"); ifModSinceStr != "" {
modules/caddyhttp/fileserver/staticfiles.go
+6
-1
@@ -375,6 +375,12 @@ func (fsrv *FileServer) ServeHTTP(w http.ResponseWriter, r *http.Request, next c
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// etag is usually unset, but if the user knows what they're doing, let them override it
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etag := w.Header().Get("Etag")
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+ // static file responses are often compressed, either on-the-fly
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+ // or with precompressed sidecar files; in any case, the headers
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+ // should contain "Vary: Accept-Encoding" even when not compressed
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+ // so caches can craft a reliable key (according to REDbot results)
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+ w.Header().Add("Vary", "Accept-Encoding")
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+
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// check for precompressed files
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for _, ae := range encode.AcceptedEncodings(r, fsrv.PrecompressedOrder) {
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precompress, ok := fsrv.precompressors[ae]
@@ -400,7 +406,6 @@ func (fsrv *FileServer) ServeHTTP(w http.ResponseWriter, r *http.Request, next c
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defer file.Close()
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w.Header().Set("Content-Encoding", ae)
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w.Header().Del("Accept-Ranges")
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- w.Header().Add("Vary", "Accept-Encoding")
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// try to get the etag from pre computed files if an etag suffix list was provided
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if etag == "" && fsrv.EtagFileExtensions != nil {