settings: fix/reorganize NMSettingConnection secrets code

NMSettingConnection's for_each_secret() function works in a
slightly-too-GHashTable-specific way. Reorganize the code now to make
the change to GVariants easier later.

Also, fix a few bugs:
  - In the (unlikely) case of a non-secret being stored in
    vpn.secrets, we were treating it as though it was a secret
    with flags NONE.
  - The code was comparing against NONE when it meant !AGENT_OWNED
    in a few places. (With the current set of NMSettingSecretFlags
    values, this worked, but in the future it might not.)
  - In some cases we never called for_each_secret() with the
    @remove_non_secrets flag, meaning we might have ended up
    passing non-secrets to other code.

src/settings/nm-settings-connection.c

@@ -180,9 +180,8 @@ typedef struct {
 
 /**************************************************************/
 
-/* Return TRUE to continue, FALSE to stop */
+/* Return TRUE to keep, FALSE to drop */
-typedef gboolean (*ForEachSecretFunc) (GHashTableIter *iter,
+typedef gboolean (*ForEachSecretFunc) (NMSettingSecretFlags flags,
-                                       NMSettingSecretFlags flags,
                                        gpointer user_data);
 
 static void
@@ -248,9 +247,13 @@ for_each_secret (NMConnection *self,
 				g_hash_table_iter_init (&vpn_secrets_iter, g_value_get_boxed (val));
 				while (g_hash_table_iter_next (&vpn_secrets_iter, (gpointer) &secret_name, NULL)) {
 					secret_flags = NM_SETTING_SECRET_FLAG_NONE;
-					nm_setting_get_secret_flags (setting, secret_name, &secret_flags, NULL);
+					if (!nm_setting_get_secret_flags (setting, secret_name, &secret_flags, NULL)) {
-					if (callback (&vpn_secrets_iter, secret_flags, callback_data) == FALSE)
+						if (remove_non_secrets)
-						return;
+							g_hash_table_iter_remove (&vpn_secrets_iter);
+						continue;
+					}
+					if (!callback (secret_flags, callback_data))
+						g_hash_table_iter_remove (&vpn_secrets_iter);
 				}
 			} else {
 				if (!nm_setting_get_secret_flags (setting, secret_name, &secret_flags, NULL)) {
@@ -258,13 +261,49 @@ for_each_secret (NMConnection *self,
 						g_hash_table_iter_remove (&secret_iter);
 					continue;
 				}
-				if (callback (&secret_iter, secret_flags, callback_data) == FALSE)
+				if (!callback (secret_flags, callback_data))
-					return;
+					g_hash_table_iter_remove (&secret_iter);
 			}
 		}
 	}
 }
 
+typedef gboolean (*FindSecretFunc) (NMSettingSecretFlags flags,
+                                    gpointer user_data);
+
+typedef struct {
+	FindSecretFunc find_func;
+	gpointer find_func_data;
+	gboolean found;
+} FindSecretData;
+
+static gboolean
+find_secret_for_each_func (NMSettingSecretFlags flags,
+                           gpointer user_data)
+{
+	FindSecretData *data = user_data;
+
+	if (!data->found)
+		data->found = data->find_func (flags, data->find_func_data);
+	return TRUE;
+}
+
+static gboolean
+find_secret (NMConnection *self,
+             GHashTable *secrets,
+             FindSecretFunc callback,
+             gpointer callback_data)
+{
+	FindSecretData data;
+
+	data.find_func = callback;
+	data.find_func_data = callback_data;
+	data.found = FALSE;
+
+	for_each_secret (self, secrets, FALSE, find_secret_for_each_func, &data);
+	return data.found;
+}
+
 /**************************************************************/
 
 static void
@@ -754,40 +793,31 @@ supports_secrets (NMSettingsConnection *self, const char *setting_name)
 	return TRUE;
 }
 
-static gboolean
+typedef struct {
-clear_nonagent_secrets (GHashTableIter *iter,
+	NMSettingSecretFlags required;
-                        NMSettingSecretFlags flags,
+	NMSettingSecretFlags forbidden;
-                        gpointer user_data)
+} ForEachSecretFlags;
-{
-	if (flags != NM_SETTING_SECRET_FLAG_AGENT_OWNED)
-		g_hash_table_iter_remove (iter);
-	return TRUE;
-}
 
 static gboolean
-clear_unsaved_secrets (GHashTableIter *iter,
+validate_secret_flags (NMSettingSecretFlags flags,
-                       NMSettingSecretFlags flags,
                        gpointer user_data)
 {
-	if (flags & (NM_SETTING_SECRET_FLAG_NOT_SAVED | NM_SETTING_SECRET_FLAG_NOT_REQUIRED))
+	ForEachSecretFlags *cmp_flags = user_data;
-		g_hash_table_iter_remove (iter);
-	return TRUE;
-}
 
-static gboolean
+	if (!NM_FLAGS_ALL (flags, cmp_flags->required))
-has_system_owned_secrets (GHashTableIter *iter,
+		return FALSE;
-                          NMSettingSecretFlags flags,
+	if (NM_FLAGS_ANY (flags, cmp_flags->forbidden))
-                          gpointer user_data)
-{
-	gboolean *has_system_owned = user_data;
-
-	if (flags == NM_SETTING_SECRET_FLAG_NONE) {
-		*has_system_owned = TRUE;
 		return FALSE;
-	}
 	return TRUE;
 }
 
+static gboolean
+secret_is_system_owned (NMSettingSecretFlags flags,
+                        gpointer user_data)
+{
+	return !NM_FLAGS_HAS (flags, NM_SETTING_SECRET_FLAG_AGENT_OWNED);
+}
+
 static void
 new_secrets_commit_cb (NMSettingsConnection *self,
                        GError *error,
@@ -820,6 +850,7 @@ agent_secrets_done_cb (NMAgentManager *manager,
 	GError *local = NULL;
 	GVariant *dict;
 	gboolean agent_had_system = FALSE;
+	ForEachSecretFlags cmp_flags = { NM_SETTING_SECRET_FLAG_NONE, NM_SETTING_SECRET_FLAG_NONE };
 
 	if (error) {
 		_LOGD ("(%s:%u) secrets request error: (%d) %s",
@@ -854,7 +885,7 @@ agent_secrets_done_cb (NMAgentManager *manager,
 		 * save those system-owned secrets.  If not, discard them and use the
 		 * existing secrets, or fail the connection.
 		 */
-		for_each_secret (NM_CONNECTION (self), secrets, TRUE, has_system_owned_secrets, &agent_had_system);
+		agent_had_system = find_secret (NM_CONNECTION (self), secrets, secret_is_system_owned, NULL);
 		if (agent_had_system) {
 			if (flags == NM_SECRET_AGENT_GET_SECRETS_FLAG_NONE) {
 				/* No user interaction was allowed when requesting secrets; the
@@ -865,7 +896,7 @@ agent_secrets_done_cb (NMAgentManager *manager,
 				       call_id,
 				       agent_dbus_owner);
 
-				for_each_secret (NM_CONNECTION (self), secrets, FALSE, clear_nonagent_secrets, NULL);
+				cmp_flags.required |= NM_SETTING_SECRET_FLAG_AGENT_OWNED;
 			} else if (agent_has_modify == FALSE) {
 				/* Agent didn't successfully authenticate; clear system-owned secrets
 				 * from the secrets the agent returned.
@@ -874,7 +905,7 @@ agent_secrets_done_cb (NMAgentManager *manager,
 				       setting_name,
 				       call_id);
 
-				for_each_secret (NM_CONNECTION (self), secrets, FALSE, clear_nonagent_secrets, NULL);
+				cmp_flags.required |= NM_SETTING_SECRET_FLAG_AGENT_OWNED;
 			}
 		}
 	} else {
@@ -890,8 +921,12 @@ agent_secrets_done_cb (NMAgentManager *manager,
 	/* If no user interaction was allowed, make sure that no "unsaved" secrets
 	 * came back.  Unsaved secrets by definition require user interaction.
 	 */
-	if (flags == NM_SECRET_AGENT_GET_SECRETS_FLAG_NONE)
+	if (flags == NM_SECRET_AGENT_GET_SECRETS_FLAG_NONE) {
-		for_each_secret (NM_CONNECTION (self), secrets, TRUE, clear_unsaved_secrets, NULL);
+		cmp_flags.forbidden |= (  NM_SETTING_SECRET_FLAG_NOT_SAVED
+		                        | NM_SETTING_SECRET_FLAG_NOT_REQUIRED);
+	}
+
+	for_each_secret (NM_CONNECTION (self), secrets, TRUE, validate_secret_flags, &cmp_flags);
 
 	/* Update the connection with our existing secrets from backing storage */
 	nm_connection_clear_secrets (NM_CONNECTION (self));