diff options
| -rw-r--r-- | pkg/sentry/fs/ext/BUILD | 1 | ||||
| -rw-r--r-- | pkg/sentry/fs/ext/directory.go | 4 | ||||
| -rw-r--r-- | pkg/sentry/fs/ext/ext_test.go | 120 |
3 files changed, 124 insertions, 1 deletions
diff --git a/pkg/sentry/fs/ext/BUILD b/pkg/sentry/fs/ext/BUILD index 64dc288c8..a3b1e4bd6 100644 --- a/pkg/sentry/fs/ext/BUILD +++ b/pkg/sentry/fs/ext/BUILD @@ -78,6 +78,7 @@ go_test( "//pkg/sentry/kernel/auth", "//pkg/sentry/usermem", "//pkg/sentry/vfs", + "//pkg/syserror", "//runsc/test/testutil", "@com_github_google_go-cmp//cmp:go_default_library", "@com_github_google_go-cmp//cmp/cmpopts:go_default_library", diff --git a/pkg/sentry/fs/ext/directory.go b/pkg/sentry/fs/ext/directory.go index f896dbe1d..1ba8bf54c 100644 --- a/pkg/sentry/fs/ext/directory.go +++ b/pkg/sentry/fs/ext/directory.go @@ -217,7 +217,9 @@ func (fd *directoryFD) Seek(ctx context.Context, offset int64, whence int32) (in defer dir.mu.Unlock() // Find resulting offset. - offset += fd.off + if whence == linux.SEEK_CUR { + offset += fd.off + } if offset < 0 { // lseek(2) specifies that EINVAL should be returned if the resulting offset diff --git a/pkg/sentry/fs/ext/ext_test.go b/pkg/sentry/fs/ext/ext_test.go index 81618bc0e..270f38074 100644 --- a/pkg/sentry/fs/ext/ext_test.go +++ b/pkg/sentry/fs/ext/ext_test.go @@ -31,6 +31,7 @@ import ( "gvisor.dev/gvisor/pkg/sentry/kernel/auth" "gvisor.dev/gvisor/pkg/sentry/usermem" "gvisor.dev/gvisor/pkg/sentry/vfs" + "gvisor.dev/gvisor/pkg/syserror" "gvisor.dev/gvisor/runsc/test/testutil" ) @@ -83,6 +84,125 @@ func setUp(t *testing.T, imagePath string) (context.Context, *vfs.VirtualFilesys return ctx, vfsObj, &root, tearDown, nil } +// TODO(b/134676337): Test vfs.FilesystemImpl.ReadlinkAt and +// vfs.FilesystemImpl.StatFSAt which are not implemented in +// vfs.VirtualFilesystem yet. + +// TestSeek tests vfs.FileDescriptionImpl.Seek functionality. +func TestSeek(t *testing.T) { + type seekTest struct { + name string + image string + path string + } + + tests := []seekTest{ + { + name: "ext4 root dir seek", + image: ext4ImagePath, + path: "/", + }, + { + name: "ext3 root dir seek", + image: ext3ImagePath, + path: "/", + }, + { + name: "ext2 root dir seek", + image: ext2ImagePath, + path: "/", + }, + { + name: "ext4 reg file seek", + image: ext4ImagePath, + path: "/file.txt", + }, + { + name: "ext3 reg file seek", + image: ext3ImagePath, + path: "/file.txt", + }, + { + name: "ext2 reg file seek", + image: ext2ImagePath, + path: "/file.txt", + }, + } + + for _, test := range tests { + t.Run(test.name, func(t *testing.T) { + ctx, vfsfs, root, tearDown, err := setUp(t, test.image) + if err != nil { + t.Fatalf("setUp failed: %v", err) + } + defer tearDown() + + fd, err := vfsfs.OpenAt( + ctx, + auth.CredentialsFromContext(ctx), + &vfs.PathOperation{Root: *root, Start: *root, Pathname: test.path}, + &vfs.OpenOptions{}, + ) + if err != nil { + t.Fatalf("vfsfs.OpenAt failed: %v", err) + } + + if n, err := fd.Impl().Seek(ctx, 0, linux.SEEK_SET); n != 0 || err != nil { + t.Errorf("expected seek position 0, got %d and error %v", n, err) + } + + stat, err := fd.Impl().Stat(ctx, vfs.StatOptions{}) + if err != nil { + t.Errorf("fd.stat failed for file %s in image %s: %v", test.path, test.image, err) + } + + // We should be able to seek beyond the end of file. + size := int64(stat.Size) + if n, err := fd.Impl().Seek(ctx, size, linux.SEEK_SET); n != size || err != nil { + t.Errorf("expected seek position %d, got %d and error %v", size, n, err) + } + + // EINVAL should be returned if the resulting offset is negative. + if _, err := fd.Impl().Seek(ctx, -1, linux.SEEK_SET); err != syserror.EINVAL { + t.Errorf("expected error EINVAL but got %v", err) + } + + if n, err := fd.Impl().Seek(ctx, 3, linux.SEEK_CUR); n != size+3 || err != nil { + t.Errorf("expected seek position %d, got %d and error %v", size+3, n, err) + } + + // Make sure negative offsets work with SEEK_CUR. + if n, err := fd.Impl().Seek(ctx, -2, linux.SEEK_CUR); n != size+1 || err != nil { + t.Errorf("expected seek position %d, got %d and error %v", size+1, n, err) + } + + // EINVAL should be returned if the resulting offset is negative. + if _, err := fd.Impl().Seek(ctx, -(size + 2), linux.SEEK_CUR); err != syserror.EINVAL { + t.Errorf("expected error EINVAL but got %v", err) + } + + // Make sure SEEK_END works with regular files. + switch fd.Impl().(type) { + case *regularFileFD: + // Seek back to 0. + if n, err := fd.Impl().Seek(ctx, -size, linux.SEEK_END); n != 0 || err != nil { + t.Errorf("expected seek position %d, got %d and error %v", 0, n, err) + } + + // Seek forward beyond EOF. + if n, err := fd.Impl().Seek(ctx, 1, linux.SEEK_END); n != size+1 || err != nil { + t.Errorf("expected seek position %d, got %d and error %v", size+1, n, err) + } + + // EINVAL should be returned if the resulting offset is negative. + if _, err := fd.Impl().Seek(ctx, -(size + 1), linux.SEEK_END); err != syserror.EINVAL { + t.Errorf("expected error EINVAL but got %v", err) + } + } + }) + } +} + // TestStatAt tests filesystem.StatAt functionality. func TestStatAt(t *testing.T) { type statAtTest struct { |