| /* |
| * 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 <vlib/vlib.h> |
| #include <vlib/unix/unix.h> |
| #include <sys/types.h> |
| #include <sys/stat.h> |
| #include <unistd.h> |
| |
| /* |
| * 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: |
| */ |