Better disabling of compression types

Added build tags section to README

README.md

@@ -11,6 +11,10 @@ Currently has support for reading squashfs files and extracting files and folder
 Special thanks to <https://dr-emann.github.io/squashfs/> for some VERY important information in an easy to understand format.
 Thanks also to [distri's squashfs library](https://github.com/distr1/distri/tree/master/internal/squashfs) as I referenced it to figure some things out (and double check others).
 
+## Build tags
+
+As of `v1.1.0` this library has two optional build tags: `no_gpl` and `no_obsolete`. `no_gpl` disables the ability to read archives with lzo compression due to the library's gpl license. `no_obsolete` removes "obsolete" compression types for a reduced compilation size; currently this only disable lzma compression since it's superseded by xz.
+
 ## FUSE
 
 As of `v1.0`, FUSE capabilities has been moved to [a separate library](https://github.com/CalebQ42/squashfuse).

cmd/go-unsquashfs/main.go

@@ -3,14 +3,62 @@ package main
 import (
 	"flag"
 	"fmt"
+	"io/fs"
 	"os"
+	"os/user"
+	"path/filepath"
+	"strconv"
+	"strings"
 	"time"
 
 	"github.com/CalebQ42/squashfs"
 )
 
+func userName(uid int, numeric bool) string {
+	us := strconv.Itoa(uid)
+	if numeric {
+		return us
+	}
+	if u, err := user.LookupId(us); err == nil {
+		return u.Username
+	}
+	return us
+}
+
+func groupName(gid int, numeric bool) string {
+	gs := strconv.Itoa(gid)
+	if numeric {
+		return gs
+	}
+	if g, err := user.LookupGroupId(gs); err == nil {
+		return g.Name
+	}
+	return gs
+}
+
+func printEntry(root, path string, d fs.DirEntry, numeric bool) {
+	fi, _ := d.Info()
+	sfi := fi.(squashfs.FileInfo)
+	owner := fmt.Sprintf("%s/%s",
+		userName(sfi.Uid(), numeric),
+		groupName(sfi.Gid(), numeric))
+	link := ""
+	if sfi.IsSymlink() {
+		link = " -> " + sfi.SymlinkPath()
+	}
+	fmt.Printf("%s %s %*d %s %s%s\n",
+		strings.ToLower(fi.Mode().String()),
+		owner, 26-len(owner), fi.Size(),
+		fi.ModTime().Format("2006-01-02 15:04"),
+		filepath.Join(root, path), link)
+}
+
 func main() {
 	verbose := flag.Bool("v", false, "Verbose")
+	list := flag.Bool("l", false, "List")
+	long := flag.Bool("ll", false, "List with attributes")
+	numeric := flag.Bool("lln", false, "List with attributes and numeric ids")
+	offset := flag.Int64("o", 0, "Offset")
 	ignore := flag.Bool("ip", false, "Ignore Permissions and extract all files/folders with 0755")
 	flag.Parse()
 	if len(flag.Args()) < 2 {
@@ -21,10 +69,25 @@ func main() {
 	if err != nil {
 		panic(err)
 	}
-	r, err := squashfs.NewReader(f)
+	r, err := squashfs.NewReaderAtOffset(f, *offset)
 	if err != nil {
 		panic(err)
 	}
+	if *list || *long || *numeric {
+		root := flag.Arg(1)
+		fs.WalkDir(r, ".", func(path string, d fs.DirEntry, err error) error {
+			if err != nil {
+				panic(err)
+			}
+			if *long || *numeric {
+				printEntry(root, path, d, *numeric)
+			} else {
+				fmt.Println(filepath.Join(root, path))
+			}
+			return nil
+		})
+		return
+	}
 	op := squashfs.DefaultOptions()
 	op.Verbose = *verbose
 	op.IgnorePerm = *ignore

file.go

@@ -127,7 +127,7 @@ func (f *File) ReadDir(n int) ([]fs.DirEntry, error) {
 		}
 	}
 	var out []fs.DirEntry
-	var fi fileInfo
+	var fi FileInfo
 	for _, e := range d.Entries[start:end] {
 		fi, err = f.r.newFileInfo(e)
 		if err != nil {
@@ -142,7 +142,15 @@ func (f *File) ReadDir(n int) ([]fs.DirEntry, error) {
 
 // Returns the file's fs.FileInfo
 func (f *File) Stat() (fs.FileInfo, error) {
-	return newFileInfo(f.b.Name, &f.b.Inode), nil
+	uid, err := f.b.Uid(&f.r.Low)
+	if err != nil {
+		return nil, err
+	}
+	gid, err := f.b.Gid(&f.r.Low)
+	if err != nil {
+		return nil, err
+	}
+	return newFileInfo(f.b.Name, uid, gid, &f.b.Inode), nil
 }
 
 // SymlinkPath returns the symlink's target path. Is the File isn't a symlink, returns an empty string.

file_info.go

@@ -8,48 +8,79 @@ import (
 	"github.com/CalebQ42/squashfs/low/inode"
 )
 
-type fileInfo struct {
+type FileInfo struct {
 	name     string
+	uid      uint32
+	gid      uint32
 	size     int64
+	target   string
 	perm     uint32
 	modTime  uint32
 	fileType uint16
 }
 
-func (r Reader) newFileInfo(e directory.Entry) (fileInfo, error) {
-	i, err := r.Low.InodeFromEntry(e)
+func (r Reader) newFileInfo(e directory.Entry) (FileInfo, error) {
+	b, err := r.Low.BaseFromEntry(e)
 	if err != nil {
-		return fileInfo{}, err
+		return FileInfo{}, err
 	}
-	return newFileInfo(e.Name, &i), nil
+	uid, err := b.Uid(&r.Low)
+	if err != nil {
+		return FileInfo{}, err
+	}
+	gid, err := b.Gid(&r.Low)
+	if err != nil {
+		return FileInfo{}, err
+	}
+	return newFileInfo(e.Name, uid, gid, &b.Inode), nil
 }
 
-func newFileInfo(name string, i *inode.Inode) fileInfo {
+func newFileInfo(name string, uid, gid uint32, i *inode.Inode) FileInfo {
 	var size int64
+	var target string
 	switch i.Type {
 	case inode.Fil:
 		size = int64(i.Data.(inode.File).Size)
 	case inode.EFil:
 		size = int64(i.Data.(inode.EFile).Size)
+	case inode.Sym:
+		target = string(i.Data.(inode.Symlink).Target)
+	case inode.ESym:
+		target = string(i.Data.(inode.ESymlink).Target)
 	}
-	return fileInfo{
+	return FileInfo{
 		name:     name,
+		uid:      uid,
+		gid:      gid,
 		size:     size,
+		target:   target,
 		perm:     uint32(i.Perm),
 		modTime:  i.ModTime,
 		fileType: i.Type,
 	}
 }
 
-func (f fileInfo) Name() string {
+func (f FileInfo) Name() string {
 	return f.name
 }
 
-func (f fileInfo) Size() int64 {
+func (f FileInfo) Uid() int {
+	return int(f.uid)
+}
+
+func (f FileInfo) Gid() int {
+	return int(f.gid)
+}
+
+func (f FileInfo) Size() int64 {
 	return f.size
 }
 
-func (f fileInfo) Mode() fs.FileMode {
+func (f FileInfo) SymlinkPath() string {
+	return f.target
+}
+
+func (f FileInfo) Mode() fs.FileMode {
 	switch f.fileType {
 	case inode.Dir, inode.EDir:
 		return fs.FileMode(f.perm | uint32(fs.ModeDir))
@@ -65,31 +96,31 @@ func (f fileInfo) Mode() fs.FileMode {
 	return fs.FileMode(f.perm)
 }
 
-func (f fileInfo) ModTime() time.Time {
+func (f FileInfo) ModTime() time.Time {
 	return time.Unix(int64(f.modTime), 0)
 }
 
-func (f fileInfo) IsDir() bool {
+func (f FileInfo) IsDir() bool {
 	return f.fileType == inode.Dir || f.fileType == inode.EDir
 }
 
-func (f fileInfo) IsSymlink() bool {
+func (f FileInfo) IsSymlink() bool {
 	return f.fileType == inode.Sym || f.fileType == inode.ESym
 }
 
-func (f fileInfo) IsDevice() bool {
+func (f FileInfo) IsDevice() bool {
 	return f.fileType == inode.Block || f.fileType == inode.EBlock ||
 		f.fileType == inode.Char || f.fileType == inode.EChar
 }
 
-func (f fileInfo) IsFifo() bool {
+func (f FileInfo) IsFifo() bool {
 	return f.fileType == inode.Fifo || f.fileType == inode.EFifo
 }
 
-func (f fileInfo) IsSocket() bool {
+func (f FileInfo) IsSocket() bool {
 	return f.fileType == inode.Sock || f.fileType == inode.ESock
 }
 
-func (f fileInfo) Sys() any {
+func (f FileInfo) Sys() any {
 	return nil
 }

go.sum

@@ -1,9 +1,5 @@
-github.com/klauspost/compress v1.17.9 h1:6KIumPrER1LHsvBVuDa0r5xaG0Es51mhhB9BQB2qeMA=
-github.com/klauspost/compress v1.17.9/go.mod h1:Di0epgTjJY877eYKx5yC51cX2A2Vl2ibi7bDH9ttBbw=
 github.com/klauspost/compress v1.18.0 h1:c/Cqfb0r+Yi+JtIEq73FWXVkRonBlf0CRNYc8Zttxdo=
 github.com/klauspost/compress v1.18.0/go.mod h1:2Pp+KzxcywXVXMr50+X0Q/Lsb43OQHYWRCY2AiWywWQ=
-github.com/pierrec/lz4/v4 v4.1.21 h1:yOVMLb6qSIDP67pl/5F7RepeKYu/VmTyEXvuMI5d9mQ=
-github.com/pierrec/lz4/v4 v4.1.21/go.mod h1:gZWDp/Ze/IJXGXf23ltt2EXimqmTUXEy0GFuRQyBid4=
 github.com/pierrec/lz4/v4 v4.1.22 h1:cKFw6uJDK+/gfw5BcDL0JL5aBsAFdsIT18eRtLj7VIU=
 github.com/pierrec/lz4/v4 v4.1.22/go.mod h1:gZWDp/Ze/IJXGXf23ltt2EXimqmTUXEy0GFuRQyBid4=
 github.com/rasky/go-lzo v0.0.0-20200203143853-96a758eda86e h1:dCWirM5F3wMY+cmRda/B1BiPsFtmzXqV9b0hLWtVBMs=

internal/decompress/lzma.go

@@ -1,3 +1,5 @@
+//go:build !no_obsolete
+
 package decompress
 
 import (
@@ -9,6 +11,10 @@ import (
 
 type Lzma struct{}
 
+func NewLzma() (Lzma, error) {
+	return Lzma{}, nil
+}
+
 func (l Lzma) Decompress(data []byte) ([]byte, error) {
 	rdr, err := lzma.NewReader(bytes.NewReader(data))
 	if err != nil {

internal/decompress/lzma_disabled.go

@@ -0,0 +1,17 @@
+//go:build no_obsolete
+
+package decompress
+
+import (
+	"errors"
+)
+
+type Lzma struct{}
+
+func NewLzma() (Lzma, error) {
+	return Lzma{}, errors.New("lzma compression is disable in this build with no_obsolete")
+}
+
+func (l Lzma) Decompress(data []byte) ([]byte, error) {
+	return nil, errors.New("lzma compression is disable in this build with no_obsolete")
+}

internal/decompress/lzo.go

@@ -1,3 +1,5 @@
+//go:build !no_gpl
+
 package decompress
 
 import (
@@ -8,6 +10,10 @@ import (
 
 type Lzo struct{}
 
+func NewLzo() (Lzo, error) {
+	return Lzo{}, nil
+}
+
 func (l Lzo) Decompress(data []byte) ([]byte, error) {
 	return lzo.Decompress1X(bytes.NewReader(data), len(data), 0)
 }

internal/decompress/lzo_disabled.go

@@ -0,0 +1,15 @@
+//go:build no_gpl
+
+package decompress
+
+import "errors"
+
+type Lzo struct{}
+
+func NewLzo() (Lzo, error) {
+	return Lzo{}, errors.New("lzo compression is disable in this build with no_gpl")
+}
+
+func (l Lzo) Decompress(data []byte) ([]byte, error) {
+	return nil, errors.New("lzo compression is disable in this build with no_gpl")
+}

low/reader.go

@@ -59,15 +59,21 @@ func NewReader(r io.ReaderAt) (rdr *Reader, err error) {
 	case ZlibCompression:
 		rdr.d = decompress.Zlib{}
 	case LZMACompression:
-		rdr.d = decompress.Lzma{}
+		rdr.d, err = decompress.NewLzma()
+		if err != nil {
+			return nil, err
+		}
 	case LZOCompression:
-		rdr.d = decompress.Lzo{}
+		rdr.d, err = decompress.NewLzo()
+		if err != nil {
+			return nil, err
+		}
 	case XZCompression:
 		rdr.d = decompress.Xz{}
 	case LZ4Compression:
 		rdr.d = decompress.Lz4{}
 	case ZSTDCompression:
-		rdr.d = &decompress.Zstd{}
+		rdr.d = decompress.Zstd{}
 	default:
 		return nil, errors.New("invalid compression type. possible corrupted archive")
 	}