tests: reverse: check Access() call

internal/fusefrontend_reverse/rpath.go

@@ -70,9 +70,9 @@ func (rfs *ReverseFS) rDecryptName(cName string, dirIV []byte, pDir string) (pNa
 		}
 	} else {
 		// It makes no sense to decrypt a ".name" file. This is a virtual file
-		// that has no represantation in the plaintext filesystem. ".name"
+		// that has no representation in the plaintext filesystem. ".name"
 		// files should have already been handled in virtualfile.go.
-		tlog.Warn.Printf("decryptPath: tried to decrypt %q!? Returning EINVAL.", cName)
+		tlog.Warn.Printf("rDecryptName: cannot decrypt virtual file %q", cName)
 		return "", syscall.EINVAL
 	}
 	return pName, nil

tests/reverse/correctness_test.go

@@ -3,6 +3,7 @@ package reverse_test
 import (
 	"io/ioutil"
 	"os"
+	"syscall"
 	"testing"
 
 	"github.com/rfjakob/gocryptfs/tests/test_helpers"
@@ -65,3 +66,26 @@ func TestConfigMapping(t *testing.T) {
 		t.Errorf("empty file")
 	}
 }
+
+// Check that the access() syscall works on virtual files
+func TestAccessVirtual(t *testing.T) {
+	if plaintextnames {
+		t.Skip()
+	}
+	var R_OK uint32 = 4
+	var W_OK uint32 = 2
+	var X_OK uint32 = 1
+	fn := dirB + "/gocryptfs.diriv"
+	err := syscall.Access(fn, R_OK)
+	if err != nil {
+		t.Errorf("%q should be readable, but got error: %v", fn, err)
+	}
+	err = syscall.Access(fn, W_OK)
+	if err == nil {
+		t.Errorf("should NOT be writeable")
+	}
+	err = syscall.Access(fn, X_OK)
+	if err == nil {
+		t.Errorf("should NOT be executable")
+	}
+}

tests/reverse/main_test.go

@@ -8,10 +8,20 @@ import (
 	"github.com/rfjakob/gocryptfs/tests/test_helpers"
 )
 
-var dirA, dirB, dirC string
 var x240 = string(bytes.Repeat([]byte("x"), 240))
 var plaintextnames bool
 
+// dirA is a normal directory
+var dirA string
+
+// dirB is the reverse mount backed by dirA
+var dirB string
+
+// dirC is a forward mount backed by dirB
+var dirC string
+
+// Create directory "dirA", mount it reverse to "dirB", mount it forward
+// to "dirC".
 func TestMain(m *testing.M) {
 	var r int
 	for _, plaintextnames = range []bool{false, true} {