X-Git-Url: https://git.arvados.org/arvados.git/blobdiff_plain/767e1199d0e1bdf2b564b5c58a91d29141eb67d7..f4ca9ad94a6bb006d1f3c7ba207837f1736d1247:/services/keep-web/handler.go

diff --git a/services/keep-web/handler.go b/services/keep-web/handler.go
index 3e38cc35ca..e1b23621af 100644
--- a/services/keep-web/handler.go
+++ b/services/keep-web/handler.go
@@ -9,6 +9,8 @@ import (
 	"net/http"
 	"net/url"
 	"os"
+	"regexp"
+	"strconv"
 	"strings"
 
 	"git.curoverse.com/arvados.git/sdk/go/arvadosclient"
@@ -98,6 +100,15 @@ func (h *handler) ServeHTTP(wOrig http.ResponseWriter, r *http.Request) {
 		return
 	}
 
+	if r.Header.Get("Origin") != "" {
+		// Allow simple cross-origin requests without user
+		// credentials ("user credentials" as defined by CORS,
+		// i.e., cookies, HTTP authentication, and client-side
+		// SSL certificates. See
+		// http://www.w3.org/TR/cors/#user-credentials).
+		w.Header().Set("Access-Control-Allow-Origin", "*")
+	}
+
 	arv := clientPool.Get()
 	if arv == nil {
 		statusCode, statusText = http.StatusInternalServerError, "Pool failed: "+clientPool.Err().Error()
@@ -147,7 +158,24 @@ func (h *handler) ServeHTTP(wOrig http.ResponseWriter, r *http.Request) {
 		statusCode = http.StatusNotFound
 		return
 	}
-	if t := r.FormValue("api_token"); t != "" {
+
+	formToken := r.FormValue("api_token")
+	if formToken != "" && r.Header.Get("Origin") != "" && attachment && r.URL.Query().Get("api_token") == "" {
+		// The client provided an explicit token in the POST
+		// body. The Origin header indicates this *might* be
+		// an AJAX request, in which case redirect-with-cookie
+		// won't work: we should just serve the content in the
+		// POST response. This is safe because:
+		//
+		// * We're supplying an attachment, not inline
+		//   content, so we don't need to convert the POST to
+		//   a GET and avoid the "really resubmit form?"
+		//   problem.
+		//
+		// * The token isn't embedded in the URL, so we don't
+		//   need to worry about bookmarks and copy/paste.
+		tokens = append(tokens, formToken)
+	} else if formToken != "" {
 		// The client provided an explicit token in the query
 		// string, or a form in POST body. We must put the
 		// token in an HttpOnly cookie, and redirect to the
@@ -177,11 +205,21 @@ func (h *handler) ServeHTTP(wOrig http.ResponseWriter, r *http.Request) {
 
 		http.SetCookie(w, &http.Cookie{
 			Name:     "arvados_api_token",
-			Value:    auth.EncodeTokenCookie([]byte(t)),
+			Value:    auth.EncodeTokenCookie([]byte(formToken)),
 			Path:     "/",
 			HttpOnly: true,
 		})
-		redir := (&url.URL{Host: r.Host, Path: r.URL.Path}).String()
+
+		// Propagate query parameters (except api_token) from
+		// the original request.
+		redirQuery := r.URL.Query()
+		redirQuery.Del("api_token")
+
+		redir := (&url.URL{
+			Host:     r.Host,
+			Path:     r.URL.Path,
+			RawQuery: redirQuery.Encode(),
+		}).String()
 
 		w.Header().Add("Location", redir)
 		statusCode, statusText = http.StatusSeeOther, redir
@@ -292,8 +330,10 @@ func (h *handler) ServeHTTP(wOrig http.ResponseWriter, r *http.Request) {
 	}
 	defer rdr.Close()
 
-	// One or both of these can be -1 if not found:
 	basenamePos := strings.LastIndex(filename, "/")
+	if basenamePos < 0 {
+		basenamePos = 0
+	}
 	extPos := strings.LastIndex(filename, ".")
 	if extPos > basenamePos {
 		// Now extPos is safely >= 0.
@@ -304,13 +344,53 @@ func (h *handler) ServeHTTP(wOrig http.ResponseWriter, r *http.Request) {
 	if rdr, ok := rdr.(keepclient.ReadCloserWithLen); ok {
 		w.Header().Set("Content-Length", fmt.Sprintf("%d", rdr.Len()))
 	}
-	if attachment {
-		w.Header().Set("Content-Disposition", "attachment")
-	}
 
-	w.WriteHeader(http.StatusOK)
-	_, err = io.Copy(w, rdr)
+	applyContentDispositionHdr(w, r, filename[basenamePos:], attachment)
+	rangeRdr, statusCode := applyRangeHdr(w, r, rdr)
+
+	w.WriteHeader(statusCode)
+	_, err = io.Copy(w, rangeRdr)
 	if err != nil {
 		statusCode, statusText = http.StatusBadGateway, err.Error()
 	}
 }
+
+var rangeRe = regexp.MustCompile(`^bytes=0-([0-9]*)$`)
+
+func applyRangeHdr(w http.ResponseWriter, r *http.Request, rdr keepclient.ReadCloserWithLen) (io.Reader, int) {
+	w.Header().Set("Accept-Ranges", "bytes")
+	hdr := r.Header.Get("Range")
+	fields := rangeRe.FindStringSubmatch(hdr)
+	if fields == nil {
+		return rdr, http.StatusOK
+	}
+	rangeEnd, err := strconv.ParseInt(fields[1], 10, 64)
+	if err != nil {
+		// Empty or too big for int64 == send entire content
+		return rdr, http.StatusOK
+	}
+	if uint64(rangeEnd) >= rdr.Len() {
+		return rdr, http.StatusOK
+	}
+	w.Header().Set("Content-Length", fmt.Sprintf("%d", rangeEnd+1))
+	w.Header().Set("Content-Range", fmt.Sprintf("bytes %d-%d/%d", 0, rangeEnd, rdr.Len()))
+	return &io.LimitedReader{R: rdr, N: rangeEnd + 1}, http.StatusPartialContent
+}
+
+func applyContentDispositionHdr(w http.ResponseWriter, r *http.Request, filename string, isAttachment bool) {
+	disposition := "inline"
+	if isAttachment {
+		disposition = "attachment"
+	}
+	if strings.ContainsRune(r.RequestURI, '?') {
+		// Help the UA realize that the filename is just
+		// "filename.txt", not
+		// "filename.txt?disposition=attachment".
+		//
+		// TODO(TC): Follow advice at RFC 6266 appendix D
+		disposition += "; filename=" + strconv.QuoteToASCII(filename)
+	}
+	if disposition != "inline" {
+		w.Header().Set("Content-Disposition", disposition)
+	}
+}