fix: adjust minimum file size check for compressed archive types

* when a file is smaller than the block size and padded with zeros, compression can remove the padding, resulting in a file size less than the block size. * for compressed archive types, the check now only ensures the size is sufficient to detect the corresponding magic numbers, rather than strictly adhering to block size. Signed-off-by: Tony Chen <[email protected]>
NVIDIA · Aug 21, 2024 · 5c94da9 · 5c94da9
1 parent 7324344
commit 5c94da9
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Showing 2 changed files with 15 additions and 5 deletions.
diff --git a/cmn/archive/err.go b/cmn/archive/err.go
@@ -14,6 +14,8 @@ import (
 
 const TarBlockSize = 512 // Size of each block in a tar stream
 
+const FmtErrShortFile = "%s file is too short, should have at least %d size"
+
 // assorted errors
 type (
 	ErrUnknownMime struct{ detail string }

diff --git a/cmn/archive/mime.go b/cmn/archive/mime.go
@@ -126,7 +126,7 @@ func MimeFile(file cos.LomReader, smm *memsys.MMSA, mime, archname string) (m st
 		n         int
 		buf, slab = smm.AllocSize(sizeDetectMime)
 	)
-	m, n, err = _detect(file, archname, buf)
+	m, n, err = _detect(file, archname, m, buf)
 	if n > 0 {
 		fh, ok := file.(*os.File)
 		cos.Assertf(ok, "expecting os.File, got %T", file)
@@ -160,19 +160,27 @@ func MimeFQN(smm *memsys.MMSA, mime, archname string) (m string, err error) {
 		return "", err
 	}
 	buf, slab := smm.AllocSize(sizeDetectMime)
-	m, _, err = _detect(fh, archname, buf)
+	m, _, err = _detect(fh, archname, m, buf)
 	slab.Free(buf)
 	cos.Close(fh)
 	return
 }
 
-func _detect(file cos.LomReader, archname string, buf []byte) (m string, n int, err error) {
+func _detect(file cos.LomReader, archname, mine string, buf []byte) (m string, n int, err error) {
 	n, err = file.Read(buf)
 	if err != nil {
 		return
 	}
-	if n < sizeDetectMime {
-		err = NewErrUnknownFileExt(archname, "file is too short")
+	if mine == ExtTar && n < sizeDetectMime {
+		err = NewErrUnknownFileExt(archname, fmt.Sprintf(FmtErrShortFile, ExtTar, sizeDetectMime))
+		return
+	}
+	if mine == ExtTarGz && n < magicGzip.offset+len(magicGzip.sig) {
+		err = NewErrUnknownFileExt(archname, fmt.Sprintf(FmtErrShortFile, ExtTarGz, magicGzip.offset+len(magicGzip.sig)))
+		return
+	}
+	if mine == ExtTarLz4 && n < magicLz4.offset+len(magicLz4.sig) {
+		err = NewErrUnknownFileExt(archname, fmt.Sprintf(FmtErrShortFile, ExtTarGz, magicLz4.offset+len(magicLz4.sig)))
 		return
 	}
 	for _, magic := range allMagics {