settings-connection: add a "plugin" argument to Update2()

This will allow migrating a connection. If specified, the connection will
be confined to a particular settings plugin when written back. If the
plugin differs from the existing one, it will be removed from the old one.

introspection/org.freedesktop.NetworkManager.Settings.Connection.xml

@@ -105,7 +105,7 @@
         Update2:
         @settings: New connection settings, properties, and (optionally) secrets. Provide an empty array to use the current settings.
         @flags: Optional flags. Unknown flags cause the call to fail.
-        @args: Optional arguments dictionary, for extentibility. Currently, no arguments are accepted. Specifying unknown keys causes the call to fail.
+        @args: Optional arguments dictionary, for extentibility. Specifying unknown keys causes the call to fail.
         @result: Currently no results are returned.
         @since: 1.12
 
@@ -156,6 +156,17 @@
         </varlistentry>
         </variablelist>
 
+        The %args argument accepts the following keys:
+
+        <variablelist>
+        <varlistentry>
+          <term><literal>plugin</literal>:</term>
+          <listitem><para>The settings plugin the connection will be migrated to
+          such as "keyfile" or "ifcfg-rh".</para>
+          <para role="since">Since 1.38</para></listitem>
+        </varlistentry>
+        </variablelist>
+
         Secrets may be part of the update request, and will be either stored in persistent
         storage or sent to a Secret Agent for storage, depending on the flags
         associated with each secret.

src/core/devices/nm-device.c

@@ -3859,6 +3859,7 @@ update_external_connection(NMDevice *self)
 
     if (connection_new) {
         nm_settings_connection_update(settings_connection,
+                                      NULL,
                                       connection_new,
                                       NM_SETTINGS_CONNECTION_PERSIST_MODE_IN_MEMORY,
                                       NM_SETTINGS_CONNECTION_INT_FLAGS_NONE,

src/core/nm-checkpoint.c

@@ -231,6 +231,7 @@ restore_and_activate_connection(NMCheckpoint *self, DeviceCheckpoint *dev_checkp
             persist_mode = NM_SETTINGS_CONNECTION_PERSIST_MODE_KEEP;
             nm_settings_connection_update(
                 connection,
+                NULL,
                 dev_checkpoint->settings_connection,
                 persist_mode,
                 sett_flags,

src/core/nm-manager.c

@@ -3060,6 +3060,7 @@ recheck_assume_connection(NMManager *self, NMDevice *device)
 
                 nm_settings_connection_update(
                     sett_conn,
+                    NULL,
                     con2,
                     NM_SETTINGS_CONNECTION_PERSIST_MODE_KEEP,
                     NM_SETTINGS_CONNECTION_INT_FLAGS_NONE,

src/core/settings/nm-settings-connection.c

@@ -606,6 +606,7 @@ _secrets_update(NMConnection  *connection,
 
 gboolean
 nm_settings_connection_update(NMSettingsConnection            *self,
+                              const char                      *plugin_name,
                               NMConnection                    *new_connection,
                               NMSettingsConnectionPersistMode  persist_mode,
                               NMSettingsConnectionIntFlags     sett_flags,
@@ -618,6 +619,7 @@ nm_settings_connection_update(NMSettingsConnection            *self,
 
     return nm_settings_update_connection(NM_SETTINGS_CONNECTION_GET_PRIVATE(self)->settings,
                                          self,
+                                         plugin_name,
                                          new_connection,
                                          persist_mode,
                                          sett_flags,
@@ -835,6 +837,7 @@ nm_settings_connection_new_secrets(NMSettingsConnection *self,
 
     if (!nm_settings_connection_update(
             self,
+            NULL,
             new_connection ?: connection,
             NM_SETTINGS_CONNECTION_PERSIST_MODE_KEEP,
             NM_SETTINGS_CONNECTION_INT_FLAGS_NONE,
@@ -980,6 +983,7 @@ get_secrets_done_cb(NMAgentManager              *manager,
     }
     if (!nm_settings_connection_update(
             self,
+            NULL,
             new_connection,
             agent_had_system ? NM_SETTINGS_CONNECTION_PERSIST_MODE_KEEP
                              : NM_SETTINGS_CONNECTION_PERSIST_MODE_NO_PERSIST,
@@ -1409,6 +1413,7 @@ typedef struct {
     NMConnection          *new_settings;
     NMSettingsUpdate2Flags flags;
     char                  *audit_args;
+    char                  *plugin_name;
     bool                   is_update2 : 1;
 } UpdateInfo;
 
@@ -1436,6 +1441,7 @@ update_complete(NMSettingsConnection *self, UpdateInfo *info, GError *error)
     g_clear_object(&info->agent_mgr);
     g_clear_object(&info->new_settings);
     g_free(info->audit_args);
+    g_free(info->plugin_name);
     g_slice_free(UpdateInfo, info);
 }
 
@@ -1572,6 +1578,7 @@ update_auth_cb(NMSettingsConnection  *self,
 
     nm_settings_connection_update(
         self,
+        info->plugin_name,
         info->new_settings,
         persist_mode,
         (NM_FLAGS_HAS(info->flags, NM_SETTINGS_UPDATE2_FLAG_VOLATILE)
@@ -1642,6 +1649,7 @@ settings_connection_update(NMSettingsConnection  *self,
                            gboolean               is_update2,
                            GDBusMethodInvocation *context,
                            GVariant              *new_settings,
+                           const char            *plugin_name,
                            NMSettingsUpdate2Flags flags)
 {
     NMSettingsConnectionPrivate *priv    = NM_SETTINGS_CONNECTION_GET_PRIVATE(self);
@@ -1696,6 +1704,7 @@ settings_connection_update(NMSettingsConnection  *self,
     info->subject      = subject;
     info->flags        = flags;
     info->new_settings = tmp;
+    info->plugin_name  = g_strdup(plugin_name);
 
     permission = get_update_modify_permission(nm_settings_connection_get_connection(self),
                                               tmp ?: nm_settings_connection_get_connection(self));
@@ -1724,7 +1733,12 @@ impl_settings_connection_update(NMDBusObject                      *obj,
     gs_unref_variant GVariant *settings = NULL;
 
     g_variant_get(parameters, "(@a{sa{sv}})", &settings);
-    settings_connection_update(self, FALSE, invocation, settings, NM_SETTINGS_UPDATE2_FLAG_TO_DISK);
+    settings_connection_update(self,
+                               FALSE,
+                               invocation,
+                               settings,
+                               NULL,
+                               NM_SETTINGS_UPDATE2_FLAG_TO_DISK);
 }
 
 static void
@@ -1744,6 +1758,7 @@ impl_settings_connection_update_unsaved(NMDBusObject                      *obj,
                                FALSE,
                                invocation,
                                settings,
+                               NULL,
                                NM_SETTINGS_UPDATE2_FLAG_IN_MEMORY);
 }
 
@@ -1758,7 +1773,12 @@ impl_settings_connection_save(NMDBusObject                      *obj,
 {
     NMSettingsConnection *self = NM_SETTINGS_CONNECTION(obj);
 
-    settings_connection_update(self, FALSE, invocation, NULL, NM_SETTINGS_UPDATE2_FLAG_TO_DISK);
+    settings_connection_update(self,
+                               FALSE,
+                               invocation,
+                               NULL,
+                               NULL,
+                               NM_SETTINGS_UPDATE2_FLAG_TO_DISK);
 }
 
 static void
@@ -1770,13 +1790,15 @@ impl_settings_connection_update2(NMDBusObject                      *obj,
                                  GDBusMethodInvocation             *invocation,
                                  GVariant                          *parameters)
 {
-    NMSettingsConnection      *self     = NM_SETTINGS_CONNECTION(obj);
+    NMSettingsConnection      *self        = NM_SETTINGS_CONNECTION(obj);
-    gs_unref_variant GVariant *settings = NULL;
+    gs_unref_variant GVariant *settings    = NULL;
-    gs_unref_variant GVariant *args     = NULL;
+    gs_unref_variant GVariant *args        = NULL;
+    gs_free char              *plugin_name = NULL;
     guint32                    flags_u;
     GError                    *error = NULL;
     GVariantIter               iter;
     const char                *args_name;
+    GVariant                  *args_value;
     NMSettingsUpdate2Flags     flags;
 
     g_variant_get(parameters, "(@a{sa{sv}}u@a{sv})", &settings, &flags_u, &args);
@@ -1812,7 +1834,13 @@ impl_settings_connection_update2(NMDBusObject                      *obj,
     nm_assert(g_variant_is_of_type(args, G_VARIANT_TYPE("a{sv}")));
 
     g_variant_iter_init(&iter, args);
-    while (g_variant_iter_next(&iter, "{&sv}", &args_name, NULL)) {
+    while (g_variant_iter_next(&iter, "{&sv}", &args_name, &args_value)) {
+        if (plugin_name == NULL && nm_streq(args_name, "plugin")
+            && g_variant_is_of_type(args_value, G_VARIANT_TYPE_STRING)) {
+            plugin_name = g_variant_dup_string(args_value, NULL);
+            continue;
+        }
+
         error = g_error_new(NM_SETTINGS_ERROR,
                             NM_SETTINGS_ERROR_INVALID_ARGUMENTS,
                             "Unsupported argument '%s'",
@@ -1821,7 +1849,7 @@ impl_settings_connection_update2(NMDBusObject                      *obj,
         return;
     }
 
-    settings_connection_update(self, TRUE, invocation, settings, flags);
+    settings_connection_update(self, TRUE, invocation, settings, plugin_name, flags);
 }
 
 static void
@@ -2010,6 +2038,7 @@ dbus_clear_secrets_auth_cb(NMSettingsConnection  *self,
 
     if (!nm_settings_connection_update(
             self,
+            NULL,
             connection_cloned,
             NM_SETTINGS_CONNECTION_PERSIST_MODE_KEEP,
             NM_SETTINGS_CONNECTION_INT_FLAGS_NONE,

src/core/settings/nm-settings-connection.h

@@ -240,6 +240,7 @@ nm_settings_connection_has_unmodified_applied_connection(NMSettingsConnection *s
                                                          NMSettingCompareFlags compare_flage);
 
 gboolean nm_settings_connection_update(NMSettingsConnection            *self,
+                                       const char                      *plugin_name,
                                        NMConnection                    *new_connection,
                                        NMSettingsConnectionPersistMode  persist_mode,
                                        NMSettingsConnectionIntFlags     sett_flags,

src/core/settings/nm-settings.c

@@ -236,12 +236,16 @@ _sett_conn_entry_get_conn(SettConnEntry *sett_conn_entry)
  * update-connection. If this parameter is omitted, then it's about what happens
  * when adding a new profile (add-connection).
  *
+ * @storage_check_ignore is optional, and if given then it skips this particular
+ * storage.
+ *
  * Returns: the conflicting storage or %NULL if there is none.
  */
 static NMSettingsStorage *
 _sett_conn_entry_storage_find_conflicting_storage(SettConnEntry     *sett_conn_entry,
                                                   NMSettingsPlugin  *target_plugin,
                                                   NMSettingsStorage *storage_check_including,
+                                                  NMSettingsStorage *storage_check_ignore,
                                                   const GSList      *plugins)
 {
     StorageData *sd;
@@ -269,6 +273,12 @@ _sett_conn_entry_storage_find_conflicting_storage(SettConnEntry     *sett_conn_e
             continue;
         }
 
+        if (sd->storage == storage_check_ignore) {
+            /* We ignore this one, because we're in the process of
+             * replacing it. */
+            continue;
+        }
+
         if (sd->storage == storage_check_including) {
             /* ok, the storage is the one we are about to check. All other
              * storages are lower priority, so there is no storage that hides
@@ -1472,6 +1482,7 @@ _add_connection_to_first_plugin(NMSettings                  *self,
                                 gboolean                     shadowed_owned,
                                 NMSettingsStorage          **out_new_storage,
                                 NMConnection               **out_new_connection,
+                                NMSettingsStorage           *drop_storage,
                                 GError                     **error)
 {
     NMSettingsPrivate    *priv        = NM_SETTINGS_GET_PRIVATE(self);
@@ -1506,6 +1517,7 @@ _add_connection_to_first_plugin(NMSettings                  *self,
             conflicting_storage = _sett_conn_entry_storage_find_conflicting_storage(sett_conn_entry,
                                                                                     plugin,
                                                                                     NULL,
+                                                                                    drop_storage,
                                                                                     priv->plugins);
             if (conflicting_storage) {
                 /* we have a connection provided by a plugin with higher priority than the one
@@ -1820,6 +1832,7 @@ nm_settings_add_connection(NMSettings                     *self,
             sett_conn_entry,
             nm_settings_storage_get_plugin(shadowed_storage),
             shadowed_storage,
+            NULL,
             priv->plugins);
         if (conflicting_storage) {
             /* We cannot add the profile as @shadowed_storage, because there is another, existing storage
@@ -1853,6 +1866,7 @@ again_add_connection:
                                                   FALSE,
                                                   &new_storage,
                                                   &new_connection,
+                                                  NULL,
                                                   &local);
     } else {
         success = _update_connection_to_plugin(self,
@@ -1969,6 +1983,7 @@ again_delete_tombstone:
 gboolean
 nm_settings_update_connection(NMSettings                      *self,
                               NMSettingsConnection            *sett_conn,
+                              const char                      *plugin_name,
                               NMConnection                    *connection,
                               NMSettingsConnectionPersistMode  persist_mode,
                               NMSettingsConnectionIntFlags     sett_flags,
@@ -2175,8 +2190,9 @@ nm_settings_update_connection(NMSettings                      *self,
         } else if (nm_settings_storage_is_keyfile_lib(cur_storage)) {
             /* the profile is a keyfile in /usr/lib. It cannot be overwritten, we must migrate it
              * from /usr/lib to /etc. */
-        } else
+        } else {
             update_storage = cur_storage;
+        }
 
         if (new_in_memory) {
             if (persist_mode == NM_SETTINGS_CONNECTION_PERSIST_MODE_IN_MEMORY_ONLY) {
@@ -2195,9 +2211,22 @@ nm_settings_update_connection(NMSettings                      *self,
             }
         }
 
+        if (update_storage && plugin_name) {
+            NMSettingsPlugin *plugin = nm_settings_storage_get_plugin(update_storage);
+
+            if (strcmp(plugin_name, nm_settings_plugin_get_plugin_name(plugin))) {
+                /* We're updating a connection, we're confined to a particular
+                 * plugin, but the connection is currently using a different one.
+                 * We need to migrate. Drop the existing storage and look out for
+                 * a new one. */
+                drop_storage   = update_storage;
+                update_storage = NULL;
+            }
+        }
+
         if (!update_storage) {
             success = _add_connection_to_first_plugin(self,
-                                                      NULL,
+                                                      plugin_name,
                                                       sett_conn_entry,
                                                       connection,
                                                       new_in_memory,
@@ -2206,6 +2235,7 @@ nm_settings_update_connection(NMSettings                      *self,
                                                       new_shadowed_owned,
                                                       &new_storage,
                                                       &new_connection,
+                                                      drop_storage,
                                                       &local);
         } else {
             success = _update_connection_to_plugin(self,

src/core/settings/nm-settings.h

@@ -101,6 +101,7 @@ gboolean nm_settings_add_connection(NMSettings                     *settings,
 
 gboolean nm_settings_update_connection(NMSettings                      *self,
                                        NMSettingsConnection            *sett_conn,
+                                       const char                      *plugin_name,
                                        NMConnection                    *new_connection,
                                        NMSettingsConnectionPersistMode  persist_mode,
                                        NMSettingsConnectionIntFlags     sett_flags,