/* * 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.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(). */ /* *INDENT-OFF* */ typedef CLIB_PACKED(struct { u8 default_disabled; const char version[32]; const char version_required[32]; const char *early_init; const char *description; }) vlib_plugin_registration_t; /* *INDENT-ON* */ typedef struct { u8 *name; u8 *filename; struct stat file_info; void *handle; /* plugin registration */ vlib_plugin_registration_t *reg; char *version; } plugin_info_t; typedef struct { char *name; u8 is_disabled; u8 is_enabled; u8 skip_version_check; } plugin_config_t; typedef struct { /* loaded plugin info */ plugin_info_t *plugin_info; uword *plugin_by_name_hash; /* paths and name filters */ u8 *plugin_path; u8 *plugin_name_filter; u8 *vat_plugin_path; u8 *vat_plugin_name_filter; u8 plugins_default_disable; /* plugin configs and hash by name */ plugin_config_t *configs; uword *config_index_by_name; /* usual */ vlib_main_t *vlib_main; } plugin_main_t; extern plugin_main_t vlib_plugin_main; clib_error_t *vlib_plugin_config (vlib_main_t * vm, unformat_input_t * input); int vlib_plugin_early_init (vlib_main_t * vm); int vlib_load_new_plugins (plugin_main_t * pm, int from_early_init); void *vlib_get_plugin_symbol (char *plugin_name, char *symbol_name); u8 *vlib_get_vat_plugin_path (void); #define VLIB_PLUGIN_REGISTER() \ vlib_plugin_registration_t vlib_plugin_registration \ __attribute__((__section__(".vlib_plugin_registration"))) /* Call a plugin init function: used for init function dependencies. */ #define vlib_call_plugin_init_function(vm,p,x) \ ({ \ clib_error_t *(*_f)(vlib_main_t *); \ uword *_fptr = 0; \ clib_error_t * _error = 0; \ _fptr= vlib_get_plugin_symbol \ (p, CLIB_STRING_MACRO(_vlib_init_function_##x)); \ if (_fptr == 0) \ { \ _error = clib_error_return \ (0, "Plugin %s and/or symbol %s not found.", \ p, CLIB_STRING_MACRO(_vlib_init_function_##x)); \ } \ else \ { \ _f = (void *)(_fptr[0]); \ } \ if (_fptr && ! hash_get (vm->init_functions_called, _f)) \ { \ hash_set1 (vm->init_functions_called, _f); \ _error = _f (vm); \ } \ _error; \ }) #endif /* __included_plugin_h__ */ /* * fd.io coding-style-patch-verification: ON * * Local Variables: * eval: (c-set-style "gnu") * End: */