From dd08d3516d6a69d68adf59edf1c2a6920f9a7d1c Mon Sep 17 00:00:00 2001
From: Caleb Gardner <calebq23@gmail.com>
Date: Wed, 20 Jan 2021 14:10:14 -0600
Subject: [PATCH] Reader will now check BlockLog

---
 file.go        |  8 +-------
 reader.go      | 10 ++++++----
 reader_test.go | 11 +++--------
 writer.go      |  7 ++++---
 4 files changed, 14 insertions(+), 22 deletions(-)

diff --git a/file.go b/file.go
index c52d9fa..6b391d2 100644
--- a/file.go
+++ b/file.go
@@ -105,6 +105,7 @@ func (f *File) Sys() interface{} {
 // }
 
 //Close does nothing. It's simply here to satisfy fs.File
+//TODO: add actual implementation
 // func (f *File) Close() error {
 // 	return nil
 // }
@@ -293,13 +294,6 @@ func (f *File) Mode() os.FileMode {
 	return mode
 }
 
-//TODO: Implement with 1.16
-
-//Type returns the type bits from fs.FileMode
-// func (f *File) Type() fs.FileInfo {
-// 	return Mod() ^&fs.ModePerm
-// }
-
 //ExtractTo extracts the file to the given path. This is the same as ExtractWithOptions(path, false, false, os.ModePerm, false).
 //Will NOT try to keep symlinks valid, folders extracted will have the permissions set by the squashfs, but the folder to make path will have full permissions (777).
 //
diff --git a/reader.go b/reader.go
index 120516b..81d41c9 100644
--- a/reader.go
+++ b/reader.go
@@ -26,6 +26,8 @@ var (
 	ErrOptions = errors.New("Possibly incompatible compressor options")
 )
 
+//TODO: implement fs.FS, possibly more FS types for compatibility. Most of this work will mostly be handed off to root anyway so this shouldn't be too difficult.
+
 //Reader processes and reads a squashfs archive.
 type Reader struct {
 	r            io.ReaderAt
@@ -39,7 +41,6 @@ type Reader struct {
 
 //NewSquashfsReader returns a new squashfs.Reader from an io.ReaderAt
 func NewSquashfsReader(r io.ReaderAt) (*Reader, error) {
-	hasUnsupportedOptions := false
 	var rdr Reader
 	rdr.r = r
 	err := binary.Read(io.NewSectionReader(rdr.r, 0, int64(binary.Size(rdr.super))), binary.LittleEndian, &rdr.super)
@@ -49,9 +50,10 @@ func NewSquashfsReader(r io.ReaderAt) (*Reader, error) {
 	if rdr.super.Magic != magic {
 		return nil, errNoMagic
 	}
-	// if rdr.super.BlockLog == uint16(math.Log2(float64(rdr.super.BlockSize))) {
-	// 	return nil, errors.New("BlockSize and BlockLog doesn't match. The archive is probably corrupt")
-	// }
+	if rdr.super.BlockLog != uint16(math.Log2(float64(rdr.super.BlockSize))) {
+		return nil, errors.New("BlockSize and BlockLog doesn't match. The archive is probably corrupt")
+	}
+	hasUnsupportedOptions := false
 	rdr.flags = rdr.super.GetFlags()
 	if rdr.flags.compressorOptions {
 		switch rdr.super.CompressionType {
diff --git a/reader_test.go b/reader_test.go
index 30aacdb..8480e0a 100644
--- a/reader_test.go
+++ b/reader_test.go
@@ -3,6 +3,7 @@ package squashfs
 import (
 	"fmt"
 	"io"
+	"math"
 	"net/http"
 	"os"
 	"os/exec"
@@ -69,19 +70,13 @@ func TestAppImage(t *testing.T) {
 	}
 	defer aiFil.Close()
 	stat, _ := aiFil.Stat()
-	os.RemoveAll(wd + "/testing/firefox")
 	ai := goappimage.NewAppImage(wd + "/testing/" + appImageName)
 	rdr, err := NewSquashfsReader(io.NewSectionReader(aiFil, ai.Offset, stat.Size()-ai.Offset))
 	if err != nil {
 		t.Fatal(err)
 	}
-	desktop := rdr.GetFileAtPath("*.desktop")
-	if desktop == nil {
-		t.Fatal("Problema!")
-	}
-	os.Remove(wd + "/testing/cura.desktop")
-	deskFil, _ := os.Create(wd + "/testing/cura.desktop")
-	io.Copy(deskFil, desktop.Sys().(io.Reader))
+	fmt.Println(rdr.super.BlockLog, strconv.FormatInt(int64(rdr.super.BlockSize), 2))
+	fmt.Println(math.Log2(float64(rdr.super.BlockSize)))
 	t.Fatal("No problemo!")
 }
 
diff --git a/writer.go b/writer.go
index ff00b70..6521210 100644
--- a/writer.go
+++ b/writer.go
@@ -13,7 +13,7 @@ import (
 	"github.com/CalebQ42/squashfs/internal/compression"
 )
 
-//Writer is used to creaste squashfs archives. Currently unusable
+//Writer is used to creaste squashfs archives. Currently unusable.
 //TODO: Make usable
 type Writer struct {
 	compressor      compression.Compressor
@@ -21,8 +21,9 @@ type Writer struct {
 	symlinkTable    map[string]string //[oldpath]newpath
 	uidGUIDTable    []int
 	compressionType int
-	//BlockSize is how large the data blocks are. Can be between 4096 (4KB) and 1048576 (1 MB). Default is 1048576.
-	//If BlockSize is not inside that range, it will be set to within the range before writing
+	//BlockSize is how large the data blocks are. Can be between 4096 (4KB) and 1048576 (1 MB).
+	//If BlockSize is not inside that range, it will be set to within the range before writing.
+	//Default is 1048576.
 	BlockSize uint32
 	//Flags are the SuperblockFlags used when writing the archive.
 	//Currently Duplicates, Exportable, UncompressedXattr, NoXattr values are ignored