target: Add se_portal_group->tpg_auth_group

This patch adds an optional /auth/ configfs group to TPG context that
can be used by fabrics like iscsi-target for TPG demo-mode
authentication.

Cc: Dax Kelson <[e-mail]>
Signed-off-by: Nicholas Bellinger <[e-mail]>

drivers/target/target_core_fabric_configfs.c

···
 
 /* End of tfc_tpg_attrib_cit */
 
+/* Start of tfc_tpg_auth_cit */
+
+CONFIGFS_EATTR_OPS(target_fabric_tpg_auth, se_portal_group, tpg_auth_group);
+
+static struct configfs_item_operations target_fabric_tpg_auth_item_ops = {
+	.show_attribute		= target_fabric_tpg_auth_attr_show,
+	.store_attribute	= target_fabric_tpg_auth_attr_store,
+};
+
+TF_CIT_SETUP(tpg_auth, &target_fabric_tpg_auth_item_ops, NULL, NULL);
+
+/* End of tfc_tpg_attrib_cit */
+
 /* Start of tfc_tpg_param_cit */
 
 CONFIGFS_EATTR_OPS(target_fabric_tpg_param, se_portal_group, tpg_param_group);
···
 	se_tpg->tpg_group.default_groups[1] = &se_tpg->tpg_np_group;
 	se_tpg->tpg_group.default_groups[2] = &se_tpg->tpg_acl_group;
 	se_tpg->tpg_group.default_groups[3] = &se_tpg->tpg_attrib_group;
-	se_tpg->tpg_group.default_groups[4] = &se_tpg->tpg_param_group;
-	se_tpg->tpg_group.default_groups[5] = NULL;
+	se_tpg->tpg_group.default_groups[4] = &se_tpg->tpg_auth_group;
+	se_tpg->tpg_group.default_groups[5] = &se_tpg->tpg_param_group;
+	se_tpg->tpg_group.default_groups[6] = NULL;
 
 	config_group_init_type_name(&se_tpg->tpg_group, name,
 			&TF_CIT_TMPL(tf)->tfc_tpg_base_cit);
···
 			&TF_CIT_TMPL(tf)->tfc_tpg_nacl_cit);
 	config_group_init_type_name(&se_tpg->tpg_attrib_group, "attrib",
 			&TF_CIT_TMPL(tf)->tfc_tpg_attrib_cit);
+	config_group_init_type_name(&se_tpg->tpg_auth_group, "auth",
+			&TF_CIT_TMPL(tf)->tfc_tpg_auth_cit);
 	config_group_init_type_name(&se_tpg->tpg_param_group, "param",
 			&TF_CIT_TMPL(tf)->tfc_tpg_param_cit);
 
···
 	target_fabric_setup_tpg_np_cit(tf);
 	target_fabric_setup_tpg_np_base_cit(tf);
 	target_fabric_setup_tpg_attrib_cit(tf);
+	target_fabric_setup_tpg_auth_cit(tf);
 	target_fabric_setup_tpg_param_cit(tf);
 	target_fabric_setup_tpg_nacl_cit(tf);
 	target_fabric_setup_tpg_nacl_base_cit(tf);

include/target/target_core_base.h

···
 	struct target_core_fabric_ops *se_tpg_tfo;
 	struct se_wwn		*se_tpg_wwn;
 	struct config_group	tpg_group;
-	struct config_group	*tpg_default_groups[6];
+	struct config_group	*tpg_default_groups[7];
 	struct config_group	tpg_lun_group;
 	struct config_group	tpg_np_group;
 	struct config_group	tpg_acl_group;
 	struct config_group	tpg_attrib_group;
+	struct config_group	tpg_auth_group;
 	struct config_group	tpg_param_group;
 };
 

include/target/target_core_configfs.h

···
 	struct config_item_type tfc_tpg_np_cit;
 	struct config_item_type tfc_tpg_np_base_cit;
 	struct config_item_type tfc_tpg_attrib_cit;
+	struct config_item_type tfc_tpg_auth_cit;
 	struct config_item_type tfc_tpg_param_cit;
 	struct config_item_type tfc_tpg_nacl_cit;
 	struct config_item_type tfc_tpg_nacl_base_cit;

include/target/target_core_fabric_configfs.h

···
 	_fabric##_tpg_attrib_show_##_name,				\
 	_fabric##_tpg_attrib_store_##_name);
 
+CONFIGFS_EATTR_STRUCT(target_fabric_tpg_auth, se_portal_group);
+#define TF_TPG_AUTH_ATTR(_fabric, _name, _mode) 			\
+static struct target_fabric_tpg_auth_attribute _fabric##_tpg_auth_##_name = \
+	__CONFIGFS_EATTR(_name, _mode,					\
+	_fabric##_tpg_auth_show_##_name,				\
+	_fabric##_tpg_auth_store_##_name);
+
+#define TF_TPG_AUTH_ATTR_RO(_fabric, _name)				\
+static struct target_fabric_tpg_auth_attribute _fabric##_tpg_auth_##_name = \
+	__CONFIGFS_EATTR_RO(_name,					\
+	_fabric##_tpg_auth_show_##_name);
 
 CONFIGFS_EATTR_STRUCT(target_fabric_tpg_param, se_portal_group);
 #define TF_TPG_PARAM_ATTR(_fabric, _name, _mode)			\