package/ntfs3-mount: check NTFS signature

Signed-off-by: Liangbin Lian <jjm2473@gmail.com>

package/diy/ntfs3-mount/Makefile

@@ -1,7 +1,7 @@
 include $(TOPDIR)/rules.mk
 
 PKG_NAME:=ntfs3-mount
-PKG_RELEASE:=7
+PKG_RELEASE:=8
 
 include $(INCLUDE_DIR)/package.mk
 

package/diy/ntfs3-mount/files/mount.ntfs

@@ -1,2 +1,9 @@
 #!/bin/sh
+if [[ "$1" != "-*" ]]; then
+	head -c 11 "$1" | tail -c 8 | grep -Fwq 'NTFS    ' || {
+		echo "NTFS signature is missing." >&2
+		exit 32
+	}
+fi
+
 mount -i -t ntfs3 -o iocharset=utf8,force "$@" || mount -i -t ntfs3 -o iocharset=utf8,ro "$@"