Check in gVisor.

PiperOrigin-RevId: 194583126
Change-Id: Ica1d8821a90f74e7e745962d71801c598c652463

1 files changed, 102 insertions, 0 deletions

diff --git a/pkg/sentry/fs/mounts_test.go b/pkg/sentry/fs/mounts_test.go
new file mode 100644
index 000000000..8669f3a38
--- /dev/null
+++ b/pkg/sentry/fs/mounts_test.go
@@ -0,0 +1,102 @@
+// Copyright 2018 Google Inc.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package fs_test
+
+import (
+	"testing"
+
+	"gvisor.googlesource.com/gvisor/pkg/sentry/context"
+	"gvisor.googlesource.com/gvisor/pkg/sentry/context/contexttest"
+	"gvisor.googlesource.com/gvisor/pkg/sentry/fs"
+	ramfstest "gvisor.googlesource.com/gvisor/pkg/sentry/fs/ramfs/test"
+)
+
+// Creates a new MountNamespace with filesystem:
+// /       (root dir)
+// |-foo   (dir)
+//   |-bar (file)
+func createMountNamespace(ctx context.Context) (*fs.MountNamespace, error) {
+	perms := fs.FilePermsFromMode(0777)
+	m := fs.NewNonCachingMountSource(nil, fs.MountSourceFlags{})
+
+	barFile := ramfstest.NewFile(ctx, perms)
+	fooDir := ramfstest.NewDir(ctx, map[string]*fs.Inode{
+		"bar": fs.NewInode(barFile, m, fs.StableAttr{Type: fs.RegularFile}),
+	}, perms)
+	rootDir := ramfstest.NewDir(ctx, map[string]*fs.Inode{
+		"foo": fs.NewInode(fooDir, m, fs.StableAttr{Type: fs.Directory}),
+	}, perms)
+
+	return fs.NewMountNamespace(ctx, fs.NewInode(rootDir, m, fs.StableAttr{Type: fs.Directory}))
+}
+
+func TestFindLink(t *testing.T) {
+	ctx := contexttest.Context(t)
+	mm, err := createMountNamespace(ctx)
+	if err != nil {
+		t.Fatalf("createMountNamespace failed: %v", err)
+	}
+
+	root := mm.Root()
+	defer root.DecRef()
+	foo, err := root.Walk(ctx, root, "foo")
+	if err != nil {
+		t.Fatalf("Error walking to foo: %v", err)
+	}
+
+	// Positive cases.
+	for _, tc := range []struct {
+		findPath string
+		wd       *fs.Dirent
+		wantPath string
+	}{
+		{".", root, "/"},
+		{".", foo, "/foo"},
+		{"..", foo, "/"},
+		{"../../..", foo, "/"},
+		{"///foo", foo, "/foo"},
+		{"/foo", foo, "/foo"},
+		{"/foo/bar", foo, "/foo/bar"},
+		{"/foo/.///./bar", foo, "/foo/bar"},
+		{"/foo///bar", foo, "/foo/bar"},
+		{"/foo/../foo/bar", foo, "/foo/bar"},
+		{"foo/bar", root, "/foo/bar"},
+		{"foo////bar", root, "/foo/bar"},
+		{"bar", foo, "/foo/bar"},
+	} {
+		wdPath, _ := tc.wd.FullName(root)
+		if d, err := mm.FindLink(ctx, root, tc.wd, tc.findPath, 0); err != nil {
+			t.Errorf("FindLink(%q, wd=%q) failed: %v", tc.findPath, wdPath, err)
+		} else if got, _ := d.FullName(root); got != tc.wantPath {
+			t.Errorf("FindLink(%q, wd=%q) got dirent %q, want %q", tc.findPath, wdPath, got, tc.wantPath)
+		}
+	}
+
+	// Negative cases.
+	for _, tc := range []struct {
+		findPath string
+		wd       *fs.Dirent
+	}{
+		{"bar", root},
+		{"/bar", root},
+		{"/foo/../../bar", root},
+		{"foo", foo},
+	} {
+		wdPath, _ := tc.wd.FullName(root)
+		if _, err := mm.FindLink(ctx, root, tc.wd, tc.findPath, 0); err == nil {
+			t.Errorf("FindLink(%q, wd=%q) did not return error", tc.findPath, wdPath)
+		}
+	}
+}