cmd/swarm, swarm: cross-platform Content-Type detection (#17782)

- Mime types generator (Standard "mime" package rely on system-settings, see mime.osInitMime)
- Changed swarm/api.Upload:
    - simplify I/O throttling by semaphore primitive and use file name where possible
    - f.Close() must be called in Defer - otherwise panic or future added early return will cause leak of file descriptors
    - one error was suppressed

swarm/api/http/server.go

@@ -201,6 +201,13 @@ func (s *Server) HandleBzzGet(w http.ResponseWriter, r *http.Request) {
 		defer reader.Close()
 
 		w.Header().Set("Content-Type", "application/x-tar")
+
+		fileName := uri.Addr
+		if found := path.Base(uri.Path); found != "" && found != "." && found != "/" {
+			fileName = found
+		}
+		w.Header().Set("Content-Disposition", fmt.Sprintf("inline; filename=\"%s.tar\"", fileName))
+
 		w.WriteHeader(http.StatusOK)
 		io.Copy(w, reader)
 		return
@@ -616,7 +623,7 @@ func (s *Server) HandleGetResource(w http.ResponseWriter, r *http.Request) {
 
 	// All ok, serve the retrieved update
 	log.Debug("Found update", "view", view.Hex(), "ruid", ruid)
-	w.Header().Set("Content-Type", "application/octet-stream")
+	w.Header().Set("Content-Type", api.MimeOctetStream)
 	http.ServeContent(w, r, "", time.Now(), bytes.NewReader(data))
 }
 
@@ -690,11 +697,9 @@ func (s *Server) HandleGet(w http.ResponseWriter, r *http.Request) {
 	case uri.Raw():
 		// allow the request to overwrite the content type using a query
 		// parameter
-		contentType := "application/octet-stream"
 		if typ := r.URL.Query().Get("content_type"); typ != "" {
-			contentType = typ
+			w.Header().Set("Content-Type", typ)
 		}
-		w.Header().Set("Content-Type", contentType)
 		http.ServeContent(w, r, "", time.Now(), reader)
 	case uri.Hash():
 		w.Header().Set("Content-Type", "text/plain")
@@ -850,8 +855,17 @@ func (s *Server) HandleGetFile(w http.ResponseWriter, r *http.Request) {
 		return
 	}
 
-	w.Header().Set("Content-Type", contentType)
-	http.ServeContent(w, r, "", time.Now(), newBufferedReadSeeker(reader, getFileBufferSize))
+	if contentType != "" {
+		w.Header().Set("Content-Type", contentType)
+	}
+
+	fileName := uri.Addr
+	if found := path.Base(uri.Path); found != "" && found != "." && found != "/" {
+		fileName = found
+	}
+	w.Header().Set("Content-Disposition", fmt.Sprintf("inline; filename=\"%s\"", fileName))
+
+	http.ServeContent(w, r, fileName, time.Now(), newBufferedReadSeeker(reader, getFileBufferSize))
 }
 
 // The size of buffer used for bufio.Reader on LazyChunkReader passed to

swarm/api/http/server_test.go

@@ -32,6 +32,7 @@ import (
 	"net/http"
 	"net/url"
 	"os"
+	"path"
 	"strconv"
 	"strings"
 	"testing"
@@ -764,6 +765,16 @@ func testBzzTar(encrypted bool, t *testing.T) {
 	}
 	defer resp2.Body.Close()
 
+	if h := resp2.Header.Get("Content-Type"); h != "application/x-tar" {
+		t.Fatalf("Content-Type header expected: application/x-tar, got: %s", h)
+	}
+
+	expectedFileName := string(swarmHash) + ".tar"
+	expectedContentDisposition := fmt.Sprintf("inline; filename=\"%s\"", expectedFileName)
+	if h := resp2.Header.Get("Content-Disposition"); h != expectedContentDisposition {
+		t.Fatalf("Content-Disposition header expected: %s, got: %s", expectedContentDisposition, h)
+	}
+
 	file, err := ioutil.TempFile("", "swarm-downloaded-tarball")
 	if err != nil {
 		t.Fatal(err)
@@ -1099,7 +1110,7 @@ func TestModify(t *testing.T) {
 			res, body := httpDo(testCase.method, testCase.uri, reqBody, testCase.headers, testCase.verbose, t)
 
 			if res.StatusCode != testCase.expectedStatusCode {
-				t.Fatalf("expected status code %d but got %d", testCase.expectedStatusCode, res.StatusCode)
+				t.Fatalf("expected status code %d but got %d, %s", testCase.expectedStatusCode, res.StatusCode, body)
 			}
 			if testCase.assertResponseBody != "" && !strings.Contains(body, testCase.assertResponseBody) {
 				t.Log(body)
@@ -1210,19 +1221,25 @@ func TestBzzGetFileWithResolver(t *testing.T) {
 	hash := common.HexToHash(string(swarmHash))
 	resolver.hash = &hash
 	for _, v := range []struct {
-		addr               string
-		path               string
-		expectedStatusCode int
+		addr                string
+		path                string
+		expectedStatusCode  int
+		expectedContentType string
+		expectedFileName    string
 	}{
 		{
-			addr:               string(swarmHash),
-			path:               fileNames[0],
-			expectedStatusCode: http.StatusOK,
+			addr:                string(swarmHash),
+			path:                fileNames[0],
+			expectedStatusCode:  http.StatusOK,
+			expectedContentType: "text/plain",
+			expectedFileName:    path.Base(fileNames[0]),
 		},
 		{
-			addr:               "somebogusensname",
-			path:               fileNames[0],
-			expectedStatusCode: http.StatusOK,
+			addr:                "somebogusensname",
+			path:                fileNames[0],
+			expectedStatusCode:  http.StatusOK,
+			expectedContentType: "text/plain",
+			expectedFileName:    path.Base(fileNames[0]),
 		},
 	} {
 		req, err := http.NewRequest("GET", fmt.Sprintf(srv.URL+"/bzz:/%s/%s", v.addr, v.path), nil)
@@ -1237,6 +1254,16 @@ func TestBzzGetFileWithResolver(t *testing.T) {
 		if serverResponse.StatusCode != v.expectedStatusCode {
 			t.Fatalf("expected %d, got %d", v.expectedStatusCode, serverResponse.StatusCode)
 		}
+
+		if h := serverResponse.Header.Get("Content-Type"); h != v.expectedContentType {
+			t.Fatalf("Content-Type header expected: %s, got %s", v.expectedContentType, h)
+		}
+
+		expectedContentDisposition := fmt.Sprintf("inline; filename=\"%s\"", v.expectedFileName)
+		if h := serverResponse.Header.Get("Content-Disposition"); h != expectedContentDisposition {
+			t.Fatalf("Content-Disposition header expected: %s, got: %s", expectedContentDisposition, h)
+		}
+
 	}
 }