From 7cd468a3d7dee7d6c92f69a0bb7061ae208ec727 Mon Sep 17 00:00:00 2001 From: Damjan Marion Date: Mon, 19 Dec 2016 23:05:39 +0100 Subject: Reorganize source tree to use single autotools instance Change-Id: I7b51f88292e057c6443b12224486f2d0c9f8ae23 Signed-off-by: Damjan Marion --- src/vlib/unix/plugin.h | 98 ++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 98 insertions(+) create mode 100644 src/vlib/unix/plugin.h (limited to 'src/vlib/unix/plugin.h') diff --git a/src/vlib/unix/plugin.h b/src/vlib/unix/plugin.h new file mode 100644 index 00000000000..c17053bd306 --- /dev/null +++ b/src/vlib/unix/plugin.h @@ -0,0 +1,98 @@ +/* + * plugin.h: plugin handling + * + * Copyright (c) 2011 Cisco and/or its affiliates. + * Licensed under the Apache License, Version 2.0 (the "License"); + * you may not use this file except in compliance with the License. + * You may obtain a copy of the License at: + * + * http://www.apache.org/licenses/LICENSE-2.0 + * + * Unless required by applicable law or agreed to in writing, software + * distributed under the License is distributed on an "AS IS" BASIS, + * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. + * See the License for the specific language governing permissions and + * limitations under the License. + */ + +#ifndef __included_plugin_h__ +#define __included_plugin_h__ + +#include +#include +#include +#include +#include + +/* + * vlib plugin scheme + * + * Almost anything which can be made to work in a vlib unix + * application will also work in a vlib plugin. + * + * The elf-section magic which registers static objects + * works so long as plugins are preset when the vlib unix process + * starts. But wait: there's more... + * + * If an application calls vlib_load_new_plugins() -- possibly after + * changing vlib_plugin_main.plugin_path / vlib_plugin_main.plugin_name_filter, + * -- new plugins will be loaded. That, in turn, allows considerable + * flexibility in terms of adding feature code or fixing bugs without + * requiring the data-plane process to restart. + * + * When the plugin mechanism loads a plugin, it uses dlsym to locate + * and call the plugin's function vlib_plugin_register() if it exists. + * A plugin which expects to be loaded after the vlib application + * starts uses this callback to modify the application. If vlib_plugin_register + * returns non-zero, the plugin mechanism dlclose()'s the plugin. + * + * Applications control the plugin search path and name filter by + * declaring the variables vlib_plugin_path and vlib_plugin_name_filter. + * libvlib_unix.la supplies weak references for these symbols which + * effectively disable the scheme. In order for the elf-section magic to + * work, static plugins must be loaded at the earliest possible moment. + * + * An application can change these parameters at any time and call + * vlib_load_new_plugins(). + */ + + + +typedef struct +{ + u8 *name; + struct stat file_info; + void *handle; +} plugin_info_t; + +typedef struct +{ + /* loaded plugin info */ + plugin_info_t *plugin_info; + uword *plugin_by_name_hash; + + /* path and name filter */ + u8 *plugin_path; + u8 *plugin_name_filter; + + /* handoff structure get callback */ + void *handoff_structure_get_cb; + + /* usual */ + vlib_main_t *vlib_main; +} plugin_main_t; + +extern plugin_main_t vlib_plugin_main; + +int vlib_plugin_early_init (vlib_main_t * vm); +int vlib_load_new_plugins (plugin_main_t * pm, int from_early_init); + +#endif /* __included_plugin_h__ */ + +/* + * fd.io coding-style-patch-verification: ON + * + * Local Variables: + * eval: (c-set-style "gnu") + * End: + */ -- cgit 1.2.3-korg