daemon: Add new ModifyYumRepo DBus API

This allows clients such as gnome-software to enable and disable
yum repositories.

The API is generic, but for now we only allow changing the 'enabled'
key. If needed, it's easy to allow changing other settings in the
future. See the discussion in the PR for the reasoning.

Closes: coreos#1771

src/daemon/org.projectatomic.rpmostree1.policy

@@ -138,6 +138,17 @@
     </defaults>
   </action>
 
+  <action id="org.projectatomic.rpmostree1.repo-modify">
+    <description>Modify repository settings</description>
+    <message>Authentication is required to modify repository settings</message>
+    <icon_name>package-x-generic</icon_name>
+    <defaults>
+      <allow_any>auth_admin</allow_any>
+      <allow_inactive>auth_admin</allow_inactive>
+      <allow_active>auth_admin_keep</allow_active>
+    </defaults>
+  </action>
+
   <action id="org.projectatomic.rpmostree1.client-management">
     <description>Register and unregister as a sysroot client</description>
     <message>Authentication is required to register as a sysroot client</message>

src/daemon/org.projectatomic.rpmostree1.xml

@@ -281,6 +281,13 @@
       <arg type="s" name="transaction_address" direction="out"/>
     </method>
 
+    <!-- Set options in yum .repo files -->
+    <method name="ModifyYumRepo">
+      <arg type="s" name="repo_id" direction="in"/>
+      <arg type="a{ss}" name="settings" direction="in"/>
+      <arg type="s" name="transaction_address" direction="out"/>
+    </method>
+
     <!-- Available modifiers:
          "set-refspec" (type 's')
          "set-revision" (type 's')

src/daemon/rpmostreed-os.c

@@ -111,6 +111,10 @@ os_authorize_method (GDBusInterfaceSkeleton *interface,
     {
       g_ptr_array_add (actions, "org.projectatomic.rpmostree1.repo-refresh");
     }
+  else if (g_strcmp0 (method_name, "ModifyYumRepo") == 0)
+    {
+      g_ptr_array_add (actions, "org.projectatomic.rpmostree1.repo-modify");
+    }
   else if (g_strcmp0 (method_name, "Deploy") == 0)
     {
       g_ptr_array_add (actions, "org.projectatomic.rpmostree1.deploy");
@@ -916,6 +920,60 @@ os_handle_refresh_md (RPMOSTreeOS *interface,
   return TRUE;
 }
 
+static gboolean
+os_handle_modify_yum_repo (RPMOSTreeOS *interface,
+                           GDBusMethodInvocation *invocation,
+                           const char *arg_repo_id,
+                           GVariant *arg_settings)
+{
+  glnx_unref_object OstreeSysroot *ot_sysroot = NULL;
+  g_autoptr(GCancellable) cancellable = g_cancellable_new ();
+  const char *osname;
+  GError *local_error = NULL;
+
+  /* try to merge with an existing transaction, otherwise start a new one */
+  glnx_unref_object RpmostreedTransaction *transaction = NULL;
+  RpmostreedSysroot *rsysroot = rpmostreed_sysroot_get ();
+  if (!rpmostreed_sysroot_prep_for_txn (rsysroot, invocation, &transaction, &local_error))
+    goto out;
+  if (transaction)
+    goto out;
+
+  if (!rpmostreed_sysroot_load_state (rpmostreed_sysroot_get (),
+                                      cancellable,
+                                      &ot_sysroot,
+                                      NULL,
+                                      &local_error))
+    goto out;
+
+  osname = rpmostree_os_get_name (interface);
+
+  transaction = rpmostreed_transaction_new_modify_yum_repo (invocation,
+                                                            ot_sysroot,
+                                                            osname,
+                                                            arg_repo_id,
+                                                            arg_settings,
+                                                            cancellable,
+                                                            &local_error);
+  if (transaction == NULL)
+    goto out;
+
+  rpmostreed_sysroot_set_txn (rsysroot, transaction);
+
+out:
+  if (local_error != NULL)
+    {
+      g_dbus_method_invocation_take_error (invocation, local_error);
+    }
+  else
+    {
+      const char *client_address = rpmostreed_transaction_get_client_address (transaction);
+      rpmostree_os_complete_modify_yum_repo (interface, invocation, client_address);
+    }
+
+  return TRUE;
+}
+
 /* This is an older variant of Cleanup, kept for backcompat */
 static gboolean
 os_handle_clear_rollback_target (RPMOSTreeOS *interface,
@@ -1668,6 +1726,7 @@ rpmostreed_os_iface_init (RPMOSTreeOSIface *iface)
   iface->handle_get_deployment_boot_config = os_handle_get_deployment_boot_config;
   iface->handle_kernel_args                = os_handle_kernel_args;
   iface->handle_refresh_md                 = os_handle_refresh_md;
+  iface->handle_modify_yum_repo            = os_handle_modify_yum_repo;
   iface->handle_rollback                   = os_handle_rollback;
   iface->handle_set_initramfs_state        = os_handle_set_initramfs_state;
   iface->handle_update_deployment          = os_handle_update_deployment;

src/daemon/rpmostreed-transaction-types.c

@@ -2060,6 +2060,155 @@ rpmostreed_transaction_new_refresh_md (GDBusMethodInvocation *invocation,
 
 }
 
+/* ================================ ModifyYumRepo ================================ */
+
+typedef struct {
+  RpmostreedTransaction parent;
+  char *osname;
+  char *repo_id;
+  GVariant *settings;
+} ModifyYumRepoTransaction;
+
+typedef RpmostreedTransactionClass ModifyYumRepoTransactionClass;
+
+GType modify_yum_repo_transaction_get_type (void);
+
+G_DEFINE_TYPE (ModifyYumRepoTransaction,
+               modify_yum_repo_transaction,
+               RPMOSTREED_TYPE_TRANSACTION)
+
+static void
+modify_yum_repo_transaction_finalize (GObject *object)
+{
+  ModifyYumRepoTransaction *self;
+
+  self = (ModifyYumRepoTransaction *) object;
+  g_free (self->osname);
+  g_free (self->repo_id);
+  g_variant_unref (self->settings);
+
+  G_OBJECT_CLASS (modify_yum_repo_transaction_parent_class)->finalize (object);
+}
+
+static DnfRepo *
+get_dnf_repo_by_id (RpmOstreeContext *ctx, const char *repo_id)
+{
+  DnfContext *dnfctx = rpmostree_context_get_dnf (ctx);
+
+  GPtrArray *repos = dnf_context_get_repos (dnfctx);
+  for (guint i = 0; i < repos->len; i++)
+    {
+      DnfRepo *repo = repos->pdata[i];
+      if (g_strcmp0 (dnf_repo_get_id (repo), repo_id) == 0)
+        return repo;
+    }
+
+  return NULL;
+}
+
+static gboolean
+modify_yum_repo_transaction_execute (RpmostreedTransaction *transaction,
+                                     GCancellable *cancellable,
+                                     GError **error)
+{
+  ModifyYumRepoTransaction *self = (ModifyYumRepoTransaction *) transaction;
+  OstreeSysroot *sysroot = rpmostreed_transaction_get_sysroot (transaction);
+
+  rpmostree_transaction_set_title ((RPMOSTreeTransaction*)self, "modify-yum-repo");
+
+  g_autoptr(OstreeDeployment) cfg_merge_deployment =
+    ostree_sysroot_get_merge_deployment (sysroot, self->osname);
+
+  OstreeRepo *ot_repo = ostree_sysroot_repo (sysroot);
+  g_autoptr(RpmOstreeContext) ctx = rpmostree_context_new_system (ot_repo, cancellable, error);
+
+  /* We could bypass rpmostree_context_setup() here and call dnf_context_setup() ourselves
+   * since we're not actually going to perform any installation. Though it does provide us
+   * with the right semantics for install/source_root. */
+  if (!rpmostree_context_setup (ctx, NULL, NULL, NULL, cancellable, error))
+    return FALSE;
+
+  /* point libdnf to our repos dir */
+  rpmostree_context_configure_from_deployment (ctx, sysroot, cfg_merge_deployment);
+
+  DnfRepo *repo = get_dnf_repo_by_id (ctx, self->repo_id);
+  if (repo == NULL)
+    return glnx_throw (error, "Yum repo '%s' not found", self->repo_id);
+
+  GVariantIter iter;
+  GVariant *child;
+  g_variant_iter_init (&iter, self->settings);
+  while ((child = g_variant_iter_next_value (&iter)) != NULL)
+    {
+      const char *parameter = NULL;
+      const char *value = NULL;
+      g_variant_get_child (child, 0, "&s", &parameter);
+      g_variant_get_child (child, 1, "&s", &value);
+
+      /* Only allow changing 'enabled' for now. See the discussion about changing arbitrary
+       * .repo settings in https://github.com/projectatomic/rpm-ostree/pull/1780 */
+      if (g_strcmp0 (parameter, "enabled") != 0)
+        return glnx_throw (error, "Changing '%s' not allowed in yum .repo files", parameter);
+
+      if (g_strcmp0 (value, "0") != 0 &&
+          g_strcmp0 (value, "1") != 0)
+        return glnx_throw (error, "Only '0' and '1' are allowed for the '%s' key", parameter);
+
+      if (!dnf_repo_set_data (repo, parameter, value, error))
+        return FALSE;
+    }
+
+  if (!dnf_repo_commit (repo, error))
+    return FALSE;
+
+  return TRUE;
+}
+
+static void
+modify_yum_repo_transaction_class_init (CleanupTransactionClass *class)
+{
+  GObjectClass *object_class;
+
+  object_class = G_OBJECT_CLASS (class);
+  object_class->finalize = modify_yum_repo_transaction_finalize;
+
+  class->execute = modify_yum_repo_transaction_execute;
+}
+
+static void
+modify_yum_repo_transaction_init (ModifyYumRepoTransaction *self)
+{
+}
+
+RpmostreedTransaction *
+rpmostreed_transaction_new_modify_yum_repo (GDBusMethodInvocation *invocation,
+                                            OstreeSysroot         *sysroot,
+                                            const char            *osname,
+                                            const char            *repo_id,
+                                            GVariant              *settings,
+                                            GCancellable          *cancellable,
+                                            GError               **error)
+{
+  g_return_val_if_fail (G_IS_DBUS_METHOD_INVOCATION (invocation), NULL);
+  g_return_val_if_fail (OSTREE_IS_SYSROOT (sysroot), NULL);
+
+  ModifyYumRepoTransaction *self =
+    g_initable_new (modify_yum_repo_transaction_get_type (),
+                    cancellable, error,
+                    "invocation", invocation,
+                    "sysroot-path", gs_file_get_path_cached (ostree_sysroot_get_path (sysroot)),
+                    NULL);
+
+  if (self != NULL)
+    {
+      self->osname = g_strdup (osname);
+      self->repo_id = g_strdup (repo_id);
+      self->settings = g_variant_ref (settings);
+    }
+
+  return (RpmostreedTransaction *) self;
+}
+
 /* ================================KernelArg================================ */
 
 typedef struct {

src/daemon/rpmostreed-transaction-types.h

@@ -117,6 +117,16 @@ rpmostreed_transaction_new_refresh_md (GDBusMethodInvocation *invocation,
                                        const char            *osname,
                                        GCancellable          *cancellable,
                                        GError               **error);
+
+RpmostreedTransaction *
+rpmostreed_transaction_new_modify_yum_repo (GDBusMethodInvocation *invocation,
+                                            OstreeSysroot         *sysroot,
+                                            const char            *osname,
+                                            const char            *repo_id,
+                                            GVariant              *settings,
+                                            GCancellable          *cancellable,
+                                            GError               **error);
+
 typedef enum {
   RPMOSTREE_TRANSACTION_KERNEL_ARG_FLAG_REBOOT = (1 << 0),
 } RpmOstreeTransactionKernelArgFlags;