initial unpacker

cmd/dungeondraft-unpack/dungeondraft-unpack.go

@@ -0,0 +1,76 @@
+package main
+
+import (
+	"flag"
+	"fmt"
+	"os"
+	"path/filepath"
+	"strings"
+
+	log "github.com/sirupsen/logrus"
+	"gitlab.com/ryexandrite/dungeondraft-gopackager/pkg/unpack"
+)
+
+const usageText = `Extracts the contesnts of a .dungeondraft_pack file
+Usage:
+	dungeondraft-unpack [args] <.dungeondraft_pack file> <output folder>
+Arguments:
+	-debug
+`
+
+func main() {
+	flag.Usage = usage
+	// args go here
+
+	debugPtr := flag.Bool("debug", false, "output debug info level log messages?")
+	flag.BoolVar(debugPtr, "v", false, "output debug info level log messages?")
+
+	flag.Parse()
+
+	debug := *debugPtr
+
+	if flag.NArg() < 1 {
+		fmt.Println("Error: Must provide a pack file")
+		usage()
+	} else if flag.NArg() < 2 {
+		fmt.Println("Error: Must provide a output folder")
+		usage()
+	}
+
+	packFilePath, pathErr := filepath.Abs(flag.Arg(0))
+	if pathErr != nil {
+		fmt.Println("could not get absolute path for packfile", pathErr)
+	}
+
+	packFileName := filepath.Base(packFilePath)
+	packName := strings.TrimSuffix(packFileName, filepath.Ext(packFileName))
+
+	log.SetOutput(os.Stdout)
+
+	// Only log the warning severity or above.
+	log.SetLevel(log.WarnLevel)
+	if debug {
+		log.SetLevel(log.InfoLevel)
+	}
+
+	logger := log.WithFields(log.Fields{
+		"filename": packFileName,
+	})
+
+	unpacker := unpack.NewUnpacker(logger, packName)
+
+	file, fileErr := os.Open(packFilePath)
+	if fileErr != nil {
+		log.WithField("path", packFilePath).WithError(fileErr).Fatal("Could not open file for reading.")
+	}
+
+	defer file.Close()
+
+	unpacker.ExtractPackage(file, flag.Arg(1))
+}
+
+func usage() {
+	fmt.Print(usageText)
+	flag.PrintDefaults()
+	os.Exit(2)
+}

go.mod

@@ -0,0 +1,5 @@
+module gitlab.com/ryexandrite/dungeondraft-gopackager
+
+go 1.14
+
+require github.com/sirupsen/logrus v1.6.0

go.sum

@@ -0,0 +1,8 @@
+github.com/davecgh/go-spew v1.1.1/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
+github.com/konsorten/go-windows-terminal-sequences v1.0.3 h1:CE8S1cTafDpPvMhIxNJKvHsGVBgn1xWYf1NbHQhywc8=
+github.com/konsorten/go-windows-terminal-sequences v1.0.3/go.mod h1:T0+1ngSBFLxvqU3pZ+m/2kptfBszLMUkC4ZK/EgS/cQ=
+github.com/pmezard/go-difflib v1.0.0/go.mod h1:iKH77koFhYxTK1pcRnkKkqfTogsbg7gZNVY4sRDYZ/4=
+github.com/sirupsen/logrus v1.6.0 h1:UBcNElsrwanuuMsnGSlYmtmgbb23qDR5dG+6X6Oo89I=
+github.com/sirupsen/logrus v1.6.0/go.mod h1:7uNnSEd1DgxDLC74fIahvMZmmYsHGZGEOFrfsX/uA88=
+github.com/stretchr/testify v1.2.2/go.mod h1:a8OnRcib4nhh0OaRAV+Yts87kKdq0PP7pXfy6kDkUVs=
+golang.org/x/sys v0.0.0-20190422165155-953cdadca894/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=

internal/structures/structures.go

@@ -0,0 +1,24 @@
+package structures
+
+type PackageHeadersBytes struct {
+	H1        uint32
+	H2        uint32
+	H3        uint32
+	H4        uint32
+	H5        uint32
+	H7        [16]uint32
+	FileCount uint32
+}
+
+type FileInfoBytes struct {
+	Offset uint64
+	Size   uint64
+	Md5    [16]byte
+}
+
+type FileInfo struct {
+	Path   string
+	Offset int64
+	Size   int64
+	Md5    string
+}

internal/utils/utils.go

@@ -0,0 +1,66 @@
+package utils
+
+import (
+	"bytes"
+	"encoding/binary"
+	"errors"
+	"os"
+)
+
+// DirExists tests if a Directyory exists
+func DirExists(path string) (bool, error) {
+	_, err := os.Stat(path)
+	if err == nil {
+		return true, nil
+	}
+	if os.IsNotExist(err) {
+		return false, nil
+	}
+	return false, err
+}
+
+// RipTexture detects and pulls image data from texture bytes
+func RipTexture(data []byte) (fileExt string, fileData []byte, err error) {
+
+	// webp
+	start := bytes.Index(data, []byte{0x52, 0x49, 0x46, 0x46})
+	if start >= 0 {
+		var size int32
+		err = binary.Read(bytes.NewBuffer(data[start+4:start+8]), binary.LittleEndian, size)
+		if err != nil {
+			return
+		}
+		fileExt = ".webp"
+		fileData = data[start : start+8+int(size)]
+		return
+	}
+
+	// png
+	start = bytes.Index(data, []byte{0x89, 0x50, 0x4E, 0x47, 0x0D, 0x0A, 0x1A, 0x0A})
+	if start >= 0 {
+		end := bytes.Index(data, []byte{0x49, 0x45, 0x4E, 0x44, 0xAE, 0x42, 0x60, 0x82})
+		if end < 0 {
+			err = errors.New("found PNG start but could not find PNG end tag")
+			return
+		}
+		fileExt = ".png"
+		fileData = data[start : end+8]
+		return
+	}
+
+	// jpg
+	start = bytes.Index(data, []byte{0xFF, 0xD8, 0xFF})
+	if start >= 0 {
+		end := bytes.Index(data, []byte{0xFF, 0xD9})
+		if end < 0 {
+			err = errors.New("found JPG start but could not find JPG end tag")
+			return
+		}
+		fileExt = ".jpg"
+		fileData = data[start:end]
+		return
+	}
+
+	err = errors.New("no valid image data found")
+	return
+}