1 files changed, 76 insertions, 0 deletions
diff --git a/lib/portage/binpkg.py b/lib/portage/binpkg.py
new file mode 100644
index 000000000..a48e09bdb
--- /dev/null
+++ b/lib/portage/binpkg.py
@@ -0,0 +1,76 @@
+# Copyright 2001-2020 Gentoo Authors
+# Distributed under the terms of the GNU General Public License v2
+
+import tarfile
+from portage import os
+from portage.const import SUPPORTED_XPAK_EXTENSIONS, SUPPORTED_GPKG_EXTENSIONS
+from portage.exception import InvalidBinaryPackageFormat
+from portage.output import colorize
+from portage.util import writemsg
+
+
+def get_binpkg_format(binpkg_path, check_file=False, remote=False):
+    if binpkg_path.endswith(SUPPORTED_XPAK_EXTENSIONS):
+        file_ext_format = "xpak"
+    elif binpkg_path.endswith(SUPPORTED_GPKG_EXTENSIONS):
+        file_ext_format = "gpkg"
+    else:
+        file_ext_format = None
+
+    if remote:
+        if file_ext_format is not None:
+            return file_ext_format
+        else:
+            raise InvalidBinaryPackageFormat(
+                f"Unsupported binary package format from '{binpkg_path}'"
+            )
+
+    if file_ext_format is not None and not check_file:
+        return file_ext_format
+
+    try:
+        with open(binpkg_path, "rb") as binpkg_file:
+            header = binpkg_file.read(100)
+            if b"/gpkg-1\x00" in header:
+                file_format = "gpkg"
+            else:
+                binpkg_file.seek(-16, 2)
+                tail = binpkg_file.read(16)
+                if (tail[0:8] == b"XPAKSTOP") and (tail[12:16] == b"STOP"):
+                    file_format = "xpak"
+                else:
+                    file_format = None
+
+        # check if wrong order gpkg
+        if file_format is None:
+            try:
+                with tarfile.open(binpkg_path) as gpkg_tar:
+                    if "gpkg-1" in (os.path.basename(f) for f in gpkg_tar.getnames()):
+                        file_format = "gpkg"
+            except tarfile.TarError:
+                pass
+
+    except Exception as err:
+        # We got many different exceptions here, so have to catch all of them.
+        file_format = None
+        writemsg(
+            colorize("ERR", f"Error reading binpkg '{binpkg_path}': {err}\n"),
+        )
+        raise InvalidBinaryPackageFormat(f"Error reading binpkg '{binpkg_path}': {err}")
+
+    if file_format is None:
+        raise InvalidBinaryPackageFormat(
+            f"Unsupported binary package format from '{binpkg_path}'"
+        )
+
+    if (file_ext_format is not None) and (file_ext_format != file_format):
+        writemsg(
+            colorize(
+                "WARN",
+                "File {} binpkg format mismatch, actual format: {}\n".format(
+                    binpkg_path, file_format
+                ),
+            )
+        )
+
+    return file_format