fix(image): optimized iso format check

pkg/util/fileutils2/fileutils.go

@@ -16,6 +16,7 @@ package fileutils2
 
 import (
 	"bufio"
+	"bytes"
 	"fmt"
 	"io/ioutil"
 	"os"
@@ -373,3 +374,18 @@ func GetDevUuid(dev string) (map[string]string, error) {
 	}
 	return map[string]string{}, nil
 }
+
+func IsIsoFile(sPath string) bool {
+	file, err := os.Open(sPath)
+	if err != nil {
+		return false
+	}
+	defer file.Close()
+	file.Seek(0x8001, 0)
+	buffer := make([]byte, 5)
+	_, err = file.Read(buffer)
+	if err != nil {
+		return false
+	}
+	return bytes.Equal(buffer, []byte("CD001"))
+}

pkg/util/qemuimg/qemuimg.go

@@ -211,12 +211,9 @@ func (img *SQemuImage) parse() error {
 		img.EncryptAlg = seclib2.TSymEncAlg(info.FormatSpecific.Data.Encrypt.CipherAlg)
 	}
 
-	if img.Format == qemuimgfmt.RAW && fileutils2.IsFile(img.Path) {
-		// test if it is an ISO
-		blkType := fileutils2.GetBlkidType(img.Path)
-		if utils.IsInStringArray(blkType, []string{"iso9660", "udf"}) {
-			img.Format = qemuimgfmt.ISO
-		}
+	// test if it is an ISO
+	if img.Format == qemuimgfmt.RAW && fileutils2.IsFile(img.Path) && fileutils2.IsIsoFile(img.Path) {
+		img.Format = qemuimgfmt.ISO
 	}
 	return nil
 }