Radek Krejci | 3e6632f | 2021-03-22 22:08:21 +0100 | [diff] [blame] | 1 | /** |
| 2 | * @file plugins.c |
| 3 | * @author Radek Krejci <rkrejci@cesnet.cz> |
| 4 | * @brief Manipulate with the type and extension plugins. |
| 5 | * |
| 6 | * Copyright (c) 2021 CESNET, z.s.p.o. |
| 7 | * |
| 8 | * This source code is licensed under BSD 3-Clause License (the "License"). |
| 9 | * You may not use this file except in compliance with the License. |
| 10 | * You may obtain a copy of the License at |
| 11 | * |
| 12 | * https://opensource.org/licenses/BSD-3-Clause |
| 13 | */ |
| 14 | |
| 15 | #include "plugins.h" |
| 16 | #include "plugins_internal.h" |
| 17 | |
| 18 | #include <assert.h> |
| 19 | #include <dlfcn.h> |
| 20 | #include <pthread.h> |
Radek Krejci | bf940f9 | 2021-03-24 21:04:13 +0100 | [diff] [blame^] | 21 | #include <stddef.h> |
Radek Krejci | 3e6632f | 2021-03-22 22:08:21 +0100 | [diff] [blame] | 22 | #include <string.h> |
| 23 | |
| 24 | #include "common.h" |
| 25 | #include "plugins_exts.h" |
| 26 | #include "plugins_types.h" |
| 27 | |
| 28 | /* |
| 29 | * internal type plugins records |
| 30 | */ |
| 31 | extern const struct lyplg_type_record plugins_binary[]; |
| 32 | extern const struct lyplg_type_record plugins_bits[]; |
| 33 | extern const struct lyplg_type_record plugins_boolean[]; |
| 34 | extern const struct lyplg_type_record plugins_decimal64[]; |
| 35 | extern const struct lyplg_type_record plugins_empty[]; |
| 36 | extern const struct lyplg_type_record plugins_enumeration[]; |
| 37 | extern const struct lyplg_type_record plugins_identityref[]; |
| 38 | extern const struct lyplg_type_record plugins_instanceid[]; |
| 39 | extern const struct lyplg_type_record plugins_integer[]; |
| 40 | extern const struct lyplg_type_record plugins_leafref[]; |
| 41 | extern const struct lyplg_type_record plugins_string[]; |
| 42 | extern const struct lyplg_type_record plugins_union[]; |
| 43 | |
| 44 | /* |
| 45 | * internal extension plugins records |
| 46 | */ |
| 47 | extern struct lyplg_ext_record plugins_metadata[]; |
| 48 | extern struct lyplg_ext_record plugins_nacm[]; |
| 49 | extern struct lyplg_ext_record plugins_yangdata[]; |
| 50 | |
| 51 | static pthread_mutex_t plugins_guard = PTHREAD_MUTEX_INITIALIZER; |
| 52 | |
| 53 | /** |
| 54 | * @brief Counter for currently present contexts able to refer to the loaded plugins. |
| 55 | * |
| 56 | * Plugins are shared among all the created contexts. They are loaded with the creation of the very first context and |
| 57 | * unloaded with the destroy of the last context. Therefore, to reload the list of plugins, all the contexts must be |
| 58 | * destroyed and with the creation of a first new context after that, the plugins will be reloaded. |
| 59 | */ |
| 60 | static uint32_t context_refcount = 0; |
| 61 | |
| 62 | /** |
| 63 | * @brief Record describing an implemented extension. |
| 64 | * |
| 65 | * Matches ::lyplg_ext_record and ::lyplg_type_record |
| 66 | */ |
| 67 | struct lyplg_record { |
| 68 | const char *module; /**< name of the module where the extension/type is defined */ |
| 69 | const char *revision; /**< optional module revision - if not specified, the plugin applies to any revision, |
| 70 | which is not an optimal approach due to a possible future revisions of the module. |
| 71 | Instead, there should be defined multiple items in the plugins list, each with the |
| 72 | different revision, but all with the same pointer to the plugin functions. The |
| 73 | only valid use case for the NULL revision is the case the module has no revision. */ |
| 74 | const char *name; /**< name of the extension/typedef */ |
| 75 | int8_t plugin[]; /**< specific plugin type's data - ::lyplg_ext or ::lyplg_type */ |
| 76 | }; |
| 77 | |
Radek Krejci | bf940f9 | 2021-03-24 21:04:13 +0100 | [diff] [blame^] | 78 | static struct ly_set plugins_handlers = {0}; |
Radek Krejci | 3e6632f | 2021-03-22 22:08:21 +0100 | [diff] [blame] | 79 | static struct ly_set plugins_types = {0}; |
| 80 | static struct ly_set plugins_extensions = {0}; |
| 81 | |
| 82 | /** |
Radek Krejci | bf940f9 | 2021-03-24 21:04:13 +0100 | [diff] [blame^] | 83 | * @brief Just a variadic data to cover extension and type plugins by a single ::plugins_load() function. |
| 84 | * |
| 85 | * The values are taken from ::LY_PLUGINS_EXTENSIONS and ::LYPLG_TYPES macros. |
| 86 | */ |
| 87 | static const struct { |
| 88 | const char *id; /**< string identifier: type/extension */ |
| 89 | const char *apiver_var; /**< expected variable name holding API version value */ |
| 90 | const char *plugins_var; /**< expected variable name holding plugin records */ |
| 91 | uint32_t apiver; /**< expected API version */ |
| 92 | } plugins_load_info[] = { |
| 93 | { /* LYPLG_TYPE */ |
| 94 | .id = "type", |
| 95 | .apiver_var = "plugins_types_apiver__", |
| 96 | .plugins_var = "plugins_types__", |
| 97 | .apiver = LYPLG_TYPE_API_VERSION |
| 98 | }, {/* LYPLG_EXTENSION */ |
| 99 | .id = "extension", |
| 100 | .apiver_var = "plugins_extensions_apiver__", |
| 101 | .plugins_var = "plugins_extensions__", |
| 102 | .apiver = LYPLG_EXT_API_VERSION |
| 103 | } |
| 104 | }; |
| 105 | |
| 106 | /** |
Radek Krejci | 3e6632f | 2021-03-22 22:08:21 +0100 | [diff] [blame] | 107 | * @brief Iterate over list of loaded plugins of the given @p type. |
| 108 | * |
| 109 | * @param[in] type Type of the plugins to iterate. |
| 110 | * @param[in,out] index The iterator - set to 0 for the first call. |
| 111 | * @return The plugin records, NULL if no more record is available. |
| 112 | */ |
| 113 | static struct lyplg_record * |
| 114 | plugins_iter(enum LYPLG type, uint32_t *index) |
| 115 | { |
| 116 | struct ly_set *plugins; |
| 117 | |
| 118 | assert(index); |
| 119 | |
| 120 | if (type == LYPLG_EXTENSION) { |
| 121 | plugins = &plugins_extensions; |
| 122 | } else { |
| 123 | plugins = &plugins_types; |
| 124 | } |
| 125 | |
| 126 | if (*index == plugins->count) { |
| 127 | return NULL; |
| 128 | } |
| 129 | |
| 130 | *index += 1; |
| 131 | return plugins->objs[*index - 1]; |
| 132 | } |
| 133 | |
| 134 | void * |
| 135 | lyplg_find(enum LYPLG type, const char *module, const char *revision, const char *name) |
| 136 | { |
| 137 | uint32_t i = 0; |
| 138 | struct lyplg_record *item; |
| 139 | |
| 140 | assert(module); |
| 141 | assert(name); |
| 142 | |
| 143 | while ((item = plugins_iter(type, &i)) != NULL) { |
| 144 | if (!strcmp(item->module, module) && !strcmp(item->name, name)) { |
| 145 | if (item->revision && revision && strcmp(item->revision, revision)) { |
| 146 | continue; |
| 147 | } else if (!revision && item->revision) { |
| 148 | continue; |
| 149 | } |
| 150 | |
| 151 | return &item->plugin; |
| 152 | } |
| 153 | } |
| 154 | |
| 155 | return NULL; |
| 156 | } |
| 157 | |
| 158 | /** |
| 159 | * @brief Insert the provided extension plugin records into the internal set of extension plugins for use by libyang. |
| 160 | * |
| 161 | * @param[in] recs An array of plugin records provided by the plugin implementation. The array must be terminated by a zeroed |
| 162 | * record. |
| 163 | * @return LY_SUCCESS in case of success |
| 164 | * @return LY_EINVAL for invalid information in @p recs. |
| 165 | * @return LY_EMEM in case of memory allocation failure. |
| 166 | */ |
| 167 | static LY_ERR |
| 168 | plugins_insert(enum LYPLG type, const void *recs) |
| 169 | { |
| 170 | if (!recs) { |
| 171 | return LY_SUCCESS; |
| 172 | } |
| 173 | |
| 174 | if (type == LYPLG_EXTENSION) { |
| 175 | const struct lyplg_ext_record *rec = (const struct lyplg_ext_record *)recs; |
| 176 | |
| 177 | for (uint32_t i = 0; rec[i].name; i++) { |
| 178 | LY_CHECK_RET(ly_set_add(&plugins_extensions, (void *)&rec[i], 0, NULL)); |
| 179 | } |
Radek Krejci | bf940f9 | 2021-03-24 21:04:13 +0100 | [diff] [blame^] | 180 | } else { /* LYPLG_TYPE */ |
Radek Krejci | 3e6632f | 2021-03-22 22:08:21 +0100 | [diff] [blame] | 181 | const struct lyplg_type_record *rec = (const struct lyplg_type_record *)recs; |
| 182 | |
| 183 | for (uint32_t i = 0; rec[i].name; i++) { |
| 184 | LY_CHECK_RET(ly_set_add(&plugins_types, (void *)&rec[i], 0, NULL)); |
| 185 | } |
| 186 | } |
| 187 | |
| 188 | return LY_SUCCESS; |
| 189 | } |
| 190 | |
| 191 | static void |
| 192 | lyplg_clean_(void) |
| 193 | { |
| 194 | if (--context_refcount) { |
| 195 | /* there is still some other context, do not remove the plugins */ |
| 196 | return; |
| 197 | } |
| 198 | |
| 199 | ly_set_erase(&plugins_types, NULL); |
| 200 | ly_set_erase(&plugins_extensions, NULL); |
Radek Krejci | bf940f9 | 2021-03-24 21:04:13 +0100 | [diff] [blame^] | 201 | ly_set_erase(&plugins_handlers, (void(*)(void *))dlclose); |
Radek Krejci | 3e6632f | 2021-03-22 22:08:21 +0100 | [diff] [blame] | 202 | } |
| 203 | |
| 204 | void |
| 205 | lyplg_clean(void) |
| 206 | { |
| 207 | pthread_mutex_lock(&plugins_guard); |
| 208 | lyplg_clean_(); |
| 209 | pthread_mutex_unlock(&plugins_guard); |
| 210 | } |
| 211 | |
Radek Krejci | bf940f9 | 2021-03-24 21:04:13 +0100 | [diff] [blame^] | 212 | /** |
| 213 | * @brief Get the expected plugin objects from the loaded dynamic object and add the defined plugins into the lists of |
| 214 | * available extensions/types plugins. |
| 215 | * |
| 216 | * @param[in] dlhandler Loaded dynamic library handler. |
| 217 | * @param[in] pathname Path of the loaded library for logging. |
| 218 | * @param[in] type Type of the plugins to get from the dynamic library. Note that a single library can hold both types |
| 219 | * and extensions plugins implementations, so this function should be called twice (once for each plugin type) with |
| 220 | * different @p type values |
| 221 | * @return LY_ERR values. |
| 222 | */ |
| 223 | static LY_ERR |
| 224 | plugins_load(void *dlhandler, const char *pathname, enum LYPLG type) |
| 225 | { |
| 226 | const void *plugins; |
| 227 | uint32_t *version; |
| 228 | |
| 229 | /* type plugin */ |
| 230 | version = dlsym(dlhandler, plugins_load_info[type].apiver_var); |
| 231 | if (version) { |
| 232 | /* check version ... */ |
| 233 | if (*version != plugins_load_info[type].apiver) { |
| 234 | LOGERR(NULL, LY_EINVAL, "Processing user %s plugin \"%s\" failed, wrong API version - %d expected, %d found.", |
| 235 | plugins_load_info[type].id, pathname, plugins_load_info[type].apiver, *version); |
| 236 | return LY_EINVAL; |
| 237 | } |
| 238 | |
| 239 | /* ... get types plugins information ... */ |
| 240 | if (!(plugins = dlsym(dlhandler, plugins_load_info[type].plugins_var))) { |
| 241 | char *errstr = dlerror(); |
| 242 | LOGERR(NULL, LY_EINVAL, "Processing user %s plugin \"%s\" failed, missing %s plugins information (%s).", |
| 243 | plugins_load_info[type].id, pathname, plugins_load_info[type].id, errstr); |
| 244 | return LY_EINVAL; |
| 245 | } |
| 246 | |
| 247 | /* ... and load all the types plugins */ |
| 248 | LY_CHECK_RET(plugins_insert(type, plugins)); |
| 249 | } |
| 250 | |
| 251 | return LY_SUCCESS; |
| 252 | } |
| 253 | |
| 254 | static LY_ERR |
| 255 | plugins_load_module(const char *pathname) |
| 256 | { |
| 257 | LY_ERR ret = LY_SUCCESS; |
| 258 | void *dlhandler; |
| 259 | uint32_t types_count = 0, extensions_count = 0; |
| 260 | |
| 261 | dlerror(); /* Clear any existing error */ |
| 262 | |
| 263 | dlhandler = dlopen(pathname, RTLD_NOW); |
| 264 | if (!dlhandler) { |
| 265 | LOGERR(NULL, LY_ESYS, "Loading \"%s\" as a plugin failed (%s).", pathname, dlerror()); |
| 266 | return LY_ESYS; |
| 267 | } |
| 268 | |
| 269 | if (ly_set_contains(&plugins_handlers, dlhandler, NULL)) { |
| 270 | /* the plugin is already loaded */ |
| 271 | LOGVRB("Plugin \"%s\" already loaded.", pathname); |
| 272 | |
| 273 | /* keep the correct refcount */ |
| 274 | dlclose(dlhandler); |
| 275 | return LY_SUCCESS; |
| 276 | } |
| 277 | |
| 278 | /* remember the current plugins lists for recovery */ |
| 279 | types_count = plugins_types.count; |
| 280 | extensions_count = plugins_extensions.count; |
| 281 | |
| 282 | /* type plugin */ |
| 283 | ret = plugins_load(dlhandler, pathname, LYPLG_TYPE); |
| 284 | LY_CHECK_GOTO(ret, error); |
| 285 | |
| 286 | /* extension plugin */ |
| 287 | ret = plugins_load(dlhandler, pathname, LYPLG_EXTENSION); |
| 288 | LY_CHECK_GOTO(ret, error); |
| 289 | |
| 290 | /* remember the dynamic plugin */ |
| 291 | ret = ly_set_add(&plugins_handlers, dlhandler, 1, NULL); |
| 292 | LY_CHECK_GOTO(ret, error); |
| 293 | |
| 294 | return LY_SUCCESS; |
| 295 | |
| 296 | error: |
| 297 | dlclose(dlhandler); |
| 298 | |
| 299 | /* revert changes in the lists */ |
| 300 | while (plugins_types.count > types_count) { |
| 301 | ly_set_rm_index(&plugins_types, plugins_types.count - 1, NULL); |
| 302 | } |
| 303 | while (plugins_extensions.count > extensions_count) { |
| 304 | ly_set_rm_index(&plugins_extensions, plugins_extensions.count - 1, NULL); |
| 305 | } |
| 306 | |
| 307 | return ret; |
| 308 | } |
| 309 | |
Radek Krejci | 3e6632f | 2021-03-22 22:08:21 +0100 | [diff] [blame] | 310 | LY_ERR |
| 311 | lyplg_init(void) |
| 312 | { |
| 313 | LY_ERR ret; |
| 314 | |
| 315 | pthread_mutex_lock(&plugins_guard); |
| 316 | /* let only the first context to initiate plugins, but let others wait for finishing the initiation */ |
| 317 | if (context_refcount++) { |
| 318 | /* already initiated */ |
| 319 | pthread_mutex_unlock(&plugins_guard); |
| 320 | return LY_SUCCESS; |
| 321 | } |
| 322 | |
| 323 | /* internal types */ |
| 324 | LY_CHECK_GOTO(ret = plugins_insert(LYPLG_TYPE, plugins_binary), error); |
| 325 | LY_CHECK_GOTO(ret = plugins_insert(LYPLG_TYPE, plugins_bits), error); |
| 326 | LY_CHECK_GOTO(ret = plugins_insert(LYPLG_TYPE, plugins_boolean), error); |
| 327 | LY_CHECK_GOTO(ret = plugins_insert(LYPLG_TYPE, plugins_decimal64), error); |
| 328 | LY_CHECK_GOTO(ret = plugins_insert(LYPLG_TYPE, plugins_empty), error); |
| 329 | LY_CHECK_GOTO(ret = plugins_insert(LYPLG_TYPE, plugins_enumeration), error); |
| 330 | LY_CHECK_GOTO(ret = plugins_insert(LYPLG_TYPE, plugins_identityref), error); |
| 331 | LY_CHECK_GOTO(ret = plugins_insert(LYPLG_TYPE, plugins_instanceid), error); |
| 332 | LY_CHECK_GOTO(ret = plugins_insert(LYPLG_TYPE, plugins_integer), error); |
| 333 | LY_CHECK_GOTO(ret = plugins_insert(LYPLG_TYPE, plugins_leafref), error); |
| 334 | LY_CHECK_GOTO(ret = plugins_insert(LYPLG_TYPE, plugins_string), error); |
| 335 | LY_CHECK_GOTO(ret = plugins_insert(LYPLG_TYPE, plugins_union), error); |
| 336 | |
| 337 | /* internal extensions */ |
| 338 | LY_CHECK_GOTO(ret = plugins_insert(LYPLG_EXTENSION, plugins_metadata), error); |
| 339 | LY_CHECK_GOTO(ret = plugins_insert(LYPLG_EXTENSION, plugins_nacm), error); |
| 340 | LY_CHECK_GOTO(ret = plugins_insert(LYPLG_EXTENSION, plugins_yangdata), error); |
| 341 | |
| 342 | /* initiation done, wake-up possibly waiting threads creating another contexts */ |
| 343 | pthread_mutex_unlock(&plugins_guard); |
| 344 | |
| 345 | return LY_SUCCESS; |
| 346 | |
| 347 | error: |
| 348 | /* initiation was not successful - cleanup (and let others to try) */ |
| 349 | lyplg_clean_(); |
| 350 | pthread_mutex_unlock(&plugins_guard); |
| 351 | |
| 352 | if (ret == LY_EINVAL) { |
| 353 | /* all the plugins here are internal, invalid record actually means an internal libyang error */ |
| 354 | ret = LY_EINT; |
| 355 | } |
| 356 | return ret; |
| 357 | } |
Radek Krejci | bf940f9 | 2021-03-24 21:04:13 +0100 | [diff] [blame^] | 358 | |
| 359 | API LY_ERR |
| 360 | lyplg_add(const char *pathname) |
| 361 | { |
| 362 | LY_ERR ret = LY_SUCCESS; |
| 363 | |
| 364 | LY_CHECK_ARG_RET(NULL, pathname, LY_EINVAL); |
| 365 | |
| 366 | /* works only in case a context exists */ |
| 367 | pthread_mutex_lock(&plugins_guard); |
| 368 | if (!context_refcount) { |
| 369 | /* no context */ |
| 370 | pthread_mutex_unlock(&plugins_guard); |
| 371 | LOGERR(NULL, LY_EDENIED, "To add a plugin, at least one context must exists."); |
| 372 | return LY_EDENIED; |
| 373 | } |
| 374 | |
| 375 | ret = plugins_load_module(pathname); |
| 376 | |
| 377 | pthread_mutex_unlock(&plugins_guard); |
| 378 | |
| 379 | return ret; |
| 380 | } |