libnm,core: add _nm_connection_aggregate() to replace nm_connection_for_each_setting_value()

We should no longer use nm_connection_for_each_setting_value() and
nm_setting_for_each_value(). It's fundamentally broken as it does
not work with properties that are not backed by a GObject property
and it cannot be fixed because it is public API.

Add an internal function _nm_connection_aggregate() to replace it.

Compare the implementation of the aggregation functionality inside
libnm with the previous two checks for secret-flags that it replaces:

- previous approach broke abstraction and require detailed knowledge of
  secret flags. Meaning, they must special case NMSettingVpn and
  GObject-property based secrets.
  If we implement a new way for implementing secrets (like we will need
  for WireGuard), then this the new way should only affect libnm-core,
  not require changes elsewhere.

- it's very inefficient to itereate over all settings. It involves
  cloning and sorting the list of settings, and retrieve and clone all
  GObject properties. Only to look at secret properties alone.

_nm_connection_aggregate() is supposed to be more flexible then just
the two new aggregate types that perform a "find-any" search. The
@arg argument and boolean return value can suffice to implement
different aggregation types in the future.

Also fixes the check of NMAgentManager for secret flags for VPNs
(NM_CONNECTION_AGGREGATE_ANY_SYSTEM_SECRET_FLAGS). A secret for VPNs
is a property that either has a secret or a secret-flag. The previous
implementation would only look at present secrets and
check their flags. It wouldn't check secret-flags that are
NM_SETTING_SECRET_FLAG_NONE, but have no secret.

1 files changed, 7 insertions, 0 deletions

diff --git a/libnm-core/nm-setting-private.h b/libnm-core/nm-setting-private.h
index c5a11b7a02..49d27336fa 100644
--- a/libnm-core/nm-setting-private.h
+++ b/libnm-core/nm-setting-private.h
@@ -97,6 +97,13 @@ gboolean _nm_setting_verify_secret_string (const char *str,
                                            const char *property,
                                            GError **error);
 
+gboolean _nm_setting_aggregate (NMSetting *setting,
+                                NMConnectionAggregateType type,
+                                gpointer arg);
+gboolean _nm_setting_vpn_aggregate (NMSettingVpn *setting,
+                                    NMConnectionAggregateType type,
+                                    gpointer arg);
+
 gboolean _nm_setting_slave_type_is_valid (const char *slave_type, const char **out_port_type);
 
 GVariant   *_nm_setting_to_dbus       (NMSetting *setting,