Found some good squashfs documentation so I can start work

2020-11-10 03:48:03 -06:00
parent c00ec36268
commit 40541575f8
6 changed files with 2247 additions and 0 deletions
@@ -0,0 +1,373 @@
+package squashfs
+
+import (
+	"crypto/md5"
+	"fmt"
+	"io"
+	"os"
+	"testing"
+	"time"
+
+	"github.com/google/go-cmp/cmp"
+)
+
+func cmpFileInfo(got os.FileInfo, want FileInfo) error {
+	if got, want := got.Name(), want.name; got != want {
+		return fmt.Errorf("unexpected file name: got %q, want %q", got, want)
+	}
+	if got, want := got.Size(), want.size; got != want {
+		return fmt.Errorf("unexpected size: got %d, want %d", got, want)
+	}
+	if got, want := got.IsDir(), want.mode.IsDir(); got != want {
+		return fmt.Errorf("IsDir: got %v, want %v", got, want)
+	}
+	// TODO: re-enable when it’s no longer just a change detector
+	// if got, want := got.ModTime(), want.modTime; !got.Equal(want) {
+	// 	return fmt.Errorf("IsDir: got %v, want %v", got, want)
+	// }
+
+	return nil
+}
+
+func TestReaddir(t *testing.T) {
+	t.Parallel()
+	// TODO: ship testdata files generated by mksquashfs
+	pwd, err := os.Getwd()
+	if err != nil {
+		t.Fatal(err)
+	}
+	fmt.Println(pwd + "/testdata/testing.squashfs")
+	f, err := os.Open(pwd + "/testdata/testing.squashfs")
+	if err != nil {
+		t.Fatal(err)
+	}
+	defer f.Close()
+	rd, err := NewReader(f)
+	if err != nil {
+		t.Fatal(err)
+	}
+	fis, err := rd.Readdir(rd.RootInode())
+	if err != nil {
+		t.Fatal(err)
+	}
+	for _, fi := range fis {
+		fmt.Println(fi.Name())
+	}
+	rdr, err := rd.FileReader(fis[0].Sys().(*FileInfo).Inode)
+	if err != nil {
+		t.Fatal(err)
+	}
+	err = os.Remove(pwd + "/testdata/Magisk.zip")
+	if !os.IsNotExist(err) && err != nil {
+		t.Fatal(err)
+	}
+	// rdrzlib, err := zlib.NewReader(rdr)
+	magFil, err := os.Create(pwd + "/testdata/Magisk.zip")
+	io.Copy(magFil, rdr)
+	if got, want := len(fis), 3; got != want {
+		t.Fatalf("unexpected number of directory entries: got %d, want %d", got, want)
+	}
+
+	if err := cmpFileInfo(fis[0], FileInfo{
+		name:    "bin",
+		size:    26,
+		mode:    0555 | os.ModeDir,
+		modTime: time.Unix(1581275131, 0), // stat -c %Y /ro/ack-amd64-2.24/bin
+	}); err != nil {
+		t.Fatal(err)
+	}
+
+	if err := cmpFileInfo(fis[1], FileInfo{
+		name:    "lib",
+		size:    3,
+		mode:    0555 | os.ModeDir,
+		modTime: time.Unix(1581275131, 0), // stat -c %Y /ro/ack-amd64-2.24/lib
+	}); err != nil {
+		t.Fatal(err)
+	}
+
+	if err := cmpFileInfo(fis[2], FileInfo{
+		name:    "out",
+		size:    48,
+		mode:    0555 | os.ModeDir,
+		modTime: time.Unix(1581275130, 0), // stat -c %Y /ro/ack-amd64-2.24/out
+	}); err != nil {
+		t.Fatal(err)
+	}
+
+	fis, err = rd.Readdir(fis[0].Sys().(*FileInfo).Inode)
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	if got, want := len(fis), 1; got != want {
+		t.Fatalf("unexpected number of directory entries: got %d, want %d", got, want)
+	}
+
+	if err := cmpFileInfo(fis[0], FileInfo{
+		name:    "ack",
+		size:    38400,
+		mode:    0755,
+		modTime: time.Unix(1581275131, 0), // stat -c %Y /ro/ack-amd64-2.24/bin/ack
+	}); err != nil {
+		t.Fatal(err)
+	}
+}
+
+// TestReaddirSmoke is a smoke-test, reading the root directories of SquashFS
+// images which are known to trigger code paths which were buggy.
+func TestReaddirSmoke(t *testing.T) {
+	t.Parallel()
+
+	for _, fn := range []string{
+		// bash exercises the code path where an inode is split across metadata
+		// blocks.
+		"/home/michael/distri/_build/distri/pkg/bash-amd64-5.0-4.squashfs",
+
+		// cmake exercises the code path where the root directory entries are
+		// located outside of the first block.
+		"/home/michael/distri/_build/distri/pkg/cmake-amd64-3.12.4-8.squashfs",
+	} {
+		// TODO: ship testdata files generated by mksquashfs
+		f, err := os.Open(fn)
+		if err != nil {
+			t.Fatal(err)
+		}
+		defer f.Close()
+		rd, err := NewReader(f)
+		if err != nil {
+			t.Fatal(err)
+		}
+
+		fis, err := rd.Readdir(rd.RootInode())
+		if err != nil {
+			t.Fatal(err)
+		}
+
+		if got, want := len(fis), 4; got != want {
+			t.Fatalf("unexpected number of directory entries: got %d, want %d", got, want)
+		}
+	}
+}
+
+func TestReaddirEmpty(t *testing.T) {
+	t.Parallel()
+	// TODO: ship testdata files generated by mksquashfs
+	f, err := os.Open("/home/michael/distri/_build/distri/pkg/zlib-amd64-1.2.11-4.squashfs")
+	if err != nil {
+		t.Fatal(err)
+	}
+	defer f.Close()
+	rd, err := NewReader(f)
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	fis, err := rd.Readdir(rd.RootInode())
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	if got, want := len(fis), 4; got != want {
+		t.Fatalf("unexpected number of directory entries: got %d, want %d", got, want)
+	}
+
+	if err := cmpFileInfo(fis[0], FileInfo{
+		name:    "bin",
+		size:    3,
+		mode:    0555 | os.ModeDir,
+		modTime: time.Unix(1583085224, 0), // stat -c %Y /ro/zlib-amd64-1.2.11/bin
+	}); err != nil {
+		t.Fatal(err)
+	}
+
+	fis, err = rd.Readdir(fis[0].Sys().(*FileInfo).Inode)
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	if got, want := len(fis), 0; got != want {
+		t.Fatalf("unexpected number of directory entries: got %d, want %d", got, want)
+	}
+}
+
+func TestReaddirSymlink(t *testing.T) {
+	t.Parallel()
+	// TODO: ship testdata files generated by mksquashfs
+	f, err := os.Open("/home/michael/distri/_build/distri/pkg/zlib-amd64-1.2.11-4.squashfs")
+	if err != nil {
+		t.Fatal(err)
+	}
+	defer f.Close()
+	rd, err := NewReader(f)
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	fis, err := rd.Readdir(rd.RootInode())
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	if got, want := len(fis), 4; got != want {
+		t.Fatalf("unexpected number of directory entries: got %d, want %d", got, want)
+	}
+
+	if err := cmpFileInfo(fis[3], FileInfo{
+		name:    "out",
+		size:    54,
+		mode:    0555 | os.ModeDir,
+		modTime: time.Unix(1583085224, 0), // stat -c %Y /ro/zlib-amd64-1.2.11/out
+	}); err != nil {
+		t.Fatal(err)
+	}
+
+	fis, err = rd.Readdir(fis[3].Sys().(*FileInfo).Inode)
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	if got, want := len(fis), 3; got != want {
+		t.Fatalf("unexpected number of directory entries: got %d, want %d", got, want)
+	}
+
+	if err := cmpFileInfo(fis[1], FileInfo{
+		name:    "lib",
+		size:    83,
+		mode:    0555 | os.ModeDir,
+		modTime: time.Unix(1583085224, 0), // stat -c %Y /ro/zlib-amd64-1.2.11/out/lib
+	}); err != nil {
+		t.Fatal(err)
+	}
+
+	fis, err = rd.Readdir(fis[1].Sys().(*FileInfo).Inode)
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	if got, want := len(fis), 4; got != want {
+		t.Fatalf("unexpected number of directory entries: got %d, want %d", got, want)
+	}
+
+	if err := cmpFileInfo(fis[1], FileInfo{
+		name:    "libz.so",
+		size:    9,
+		mode:    0555 | os.ModeSymlink,
+		modTime: time.Unix(1583085223, 0), // stat -c %Y /ro/zlib-amd64-1.2.11/out/lib/libz.so
+	}); err != nil {
+		t.Fatal(err)
+	}
+
+	// TODO: readlink
+	target, err := rd.ReadLink(fis[1].Sys().(*FileInfo).Inode)
+	if err != nil {
+		t.Fatal(err)
+	}
+	if got, want := target, "libz.so.1"; got != want {
+		t.Fatalf("ReadLink(libz.so): got %q, want %q", got, want)
+	}
+}
+
+func TestReadfile(t *testing.T) {
+	t.Parallel()
+	// TODO: ship testdata files generated by mksquashfs
+	f, err := os.Open("/home/michael/distri/_build/distri/pkg/ack-amd64-3.3.1-7.squashfs")
+	if err != nil {
+		t.Fatal(err)
+	}
+	defer f.Close()
+	rd, err := NewReader(f)
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	fis, err := rd.Readdir(rd.RootInode())
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	if got, want := len(fis), 3; got != want {
+		t.Fatalf("unexpected number of directory entries: got %d, want %d", got, want)
+	}
+
+	fis, err = rd.Readdir(fis[0].Sys().(*FileInfo).Inode)
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	if got, want := len(fis), 1; got != want {
+		t.Fatalf("unexpected number of directory entries: got %d, want %d", got, want)
+	}
+
+	r, err := rd.FileReader(fis[0].Sys().(*FileInfo).Inode)
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	for i := 0; i < 2; i++ {
+		if _, err := r.Seek(0, io.SeekStart); err != nil {
+			t.Fatal(err)
+		}
+		h := md5.New()
+		if _, err := io.Copy(h, r); err != nil {
+			t.Fatal(err)
+		}
+		sum := fmt.Sprintf("%x", h.Sum(nil))
+		if got, want := sum, "c6c9b5d4d2a49f1b8b5e501f0f827a5c"; got != want {
+			t.Fatalf("md5(bin/ack): got %s, want %s", got, want)
+		}
+	}
+}
+
+// TODO: add test exercising ldirInodeHeader, e.g. '/mnt/loop/ca-certificates-3.39/buildoutput/etc/ssl'
+
+func TestReadXattr(t *testing.T) {
+	t.Parallel()
+
+	// TODO: generate a smaller version of this file
+	f, err := os.Open("testdata/xattr.squashfs")
+	if err != nil {
+		t.Fatal(err)
+	}
+	defer f.Close()
+
+	rd, err := NewReader(f)
+	if err != nil {
+		t.Fatal(err)
+	}
+	for _, tt := range []struct {
+		Path string
+		Want []Xattr
+	}{
+		{
+			Path: "mtr-packet",
+			Want: []Xattr{
+				{
+					Type:     XattrTypeSecurity,
+					FullName: "security.capability",
+					Value:    []byte{1, 0, 0, 2, 0, 32, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0}},
+			},
+		},
+		{
+			Path: "gnome-keyring-daemon",
+			Want: []Xattr{
+				{
+					Type:     XattrTypeSecurity,
+					FullName: "security.capability",
+					Value:    []byte{1, 0, 0, 2, 0, 0x40, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0}},
+			},
+		},
+	} {
+		inode, err := rd.LookupPath(tt.Path)
+		if err != nil {
+			t.Fatal(err)
+		}
+		xattrs, err := rd.ReadXattrs(inode)
+		if err != nil {
+			t.Fatalf("ReadXattrs(%v): %v", inode, err)
+		}
+		if diff := cmp.Diff(tt.Want, xattrs); diff != "" {
+			t.Fatalf("unexpected ReadXattrs result: diff (-want +got):\n%s", diff)
+		}
+	}
+}