From c6b72f527bd836d810890dfc6c8efd0229157fc3 Mon Sep 17 00:00:00 2001
From: Luca BRUNO <luca.bruno@coreos.com>
Date: Thu, 19 Aug 2021 13:50:21 +0000
Subject: [PATCH] lib/core/checksum: add flag to use canonical permissions

This adds a new `OSTREE_CHECKSUM_FLAGS_CANONICAL_PERMISSIONS`
checksumming flag, which is needed in bare-user-only mode
to ignore local IDs.
---
 src/libostree/ostree-core.c | 8 ++++++++
 src/libostree/ostree-core.h | 9 +++++++++
 2 files changed, 17 insertions(+)

diff --git a/src/libostree/ostree-core.c b/src/libostree/ostree-core.c
index 6a7c2afa..aecaf31a 100644
--- a/src/libostree/ostree-core.c
+++ b/src/libostree/ostree-core.c
@@ -984,6 +984,9 @@ ostree_checksum_file_at (int               dfd,
 
   g_autoptr(GFileInfo) file_info = _ostree_stbuf_to_gfileinfo (stbuf);
 
+  const gboolean canonicalize_perms =
+    ((flags & OSTREE_CHECKSUM_FLAGS_CANONICAL_PERMISSIONS) != 0);
+
   g_autoptr(GInputStream) in = NULL;
   if (S_ISREG (stbuf->st_mode))
     {
@@ -991,6 +994,11 @@ ostree_checksum_file_at (int               dfd,
       if (!glnx_openat_rdonly (dfd, path, FALSE, &fd, error))
         return FALSE;
       in = g_unix_input_stream_new (glnx_steal_fd (&fd), TRUE);
+      if (canonicalize_perms)
+        {
+          g_file_info_set_attribute_uint32 (file_info, "unix::uid", 0);
+          g_file_info_set_attribute_uint32 (file_info, "unix::gid", 0);
+        }
     }
   else if (S_ISLNK (stbuf->st_mode))
     {
diff --git a/src/libostree/ostree-core.h b/src/libostree/ostree-core.h
index 3b903d5c..7dc1ffb7 100644
--- a/src/libostree/ostree-core.h
+++ b/src/libostree/ostree-core.h
@@ -460,12 +460,21 @@ gboolean ostree_break_hardlink (int               dfd,
 
 /**
  * OstreeChecksumFlags:
+ * @OSTREE_CHECKSUM_FLAGS_NONE: Default checksumming without tweaks.
+ *    (Since: 2017.13.)
+ * @OSTREE_CHECKSUM_FLAGS_IGNORE_XATTRS: Ignore xattrs when checksumming.
+ *    (Since: 2017.13.)
+ * @OSTREE_CHECKSUM_FLAGS_CANONICAL_PERMISSIONS: Use canonical uid/gid/mode
+ *    values, for bare-user-only mode. (Since: 2021.4.)
+ *
+ * Flags influencing checksumming logic.
  *
  * Since: 2017.13
  */
 typedef enum {
   OSTREE_CHECKSUM_FLAGS_NONE = 0,
   OSTREE_CHECKSUM_FLAGS_IGNORE_XATTRS = (1 << 0),
+  OSTREE_CHECKSUM_FLAGS_CANONICAL_PERMISSIONS = (1 << 1),
 } OstreeChecksumFlags;
 
 _OSTREE_PUBLIC