xref: /PHP-8.4/Zend/zend_extensions.c (revision 25d76162)
1 /*
2    +----------------------------------------------------------------------+
3    | Zend Engine                                                          |
4    +----------------------------------------------------------------------+
5    | Copyright (c) Zend Technologies Ltd. (http://www.zend.com)           |
6    +----------------------------------------------------------------------+
7    | This source file is subject to version 2.00 of the Zend license,     |
8    | that is bundled with this package in the file LICENSE, and is        |
9    | available through the world-wide-web at the following url:           |
10    | http://www.zend.com/license/2_00.txt.                                |
11    | If you did not receive a copy of the Zend license and are unable to  |
12    | obtain it through the world-wide-web, please send a note to          |
13    | license@zend.com so we can mail you a copy immediately.              |
14    +----------------------------------------------------------------------+
15    | Authors: Andi Gutmans <andi@php.net>                                 |
16    |          Zeev Suraski <zeev@php.net>                                 |
17    +----------------------------------------------------------------------+
18 */
19 
20 #include "zend_extensions.h"
21 #include "zend_system_id.h"
22 
23 ZEND_API zend_llist zend_extensions;
24 ZEND_API uint32_t zend_extension_flags = 0;
25 ZEND_API int zend_op_array_extension_handles = 0;
26 ZEND_API int zend_internal_function_extension_handles = 0;
27 static int last_resource_number;
28 
zend_load_extension(const char * path)29 zend_result zend_load_extension(const char *path)
30 {
31 #if ZEND_EXTENSIONS_SUPPORT
32 	DL_HANDLE handle;
33 
34 	handle = DL_LOAD(path);
35 	if (!handle) {
36 #ifndef ZEND_WIN32
37 		fprintf(stderr, "Failed loading %s:  %s\n", path, DL_ERROR());
38 #else
39 		fprintf(stderr, "Failed loading %s\n", path);
40 		/* See http://support.microsoft.com/kb/190351 */
41 		fflush(stderr);
42 #endif
43 		return FAILURE;
44 	}
45 #ifdef ZEND_WIN32
46 	char *err;
47 	if (!php_win32_image_compatible(handle, &err)) {
48 		zend_error(E_CORE_WARNING, err);
49 		return FAILURE;
50 	}
51 #endif
52 	return zend_load_extension_handle(handle, path);
53 #else
54 	fprintf(stderr, "Extensions are not supported on this platform.\n");
55 /* See http://support.microsoft.com/kb/190351 */
56 #ifdef ZEND_WIN32
57 	fflush(stderr);
58 #endif
59 	return FAILURE;
60 #endif
61 }
62 
zend_load_extension_handle(DL_HANDLE handle,const char * path)63 zend_result zend_load_extension_handle(DL_HANDLE handle, const char *path)
64 {
65 #if ZEND_EXTENSIONS_SUPPORT
66 	zend_extension *new_extension;
67 
68 	const zend_extension_version_info *extension_version_info = (const zend_extension_version_info *) DL_FETCH_SYMBOL(handle, "extension_version_info");
69 	if (!extension_version_info) {
70 		extension_version_info = (const zend_extension_version_info *) DL_FETCH_SYMBOL(handle, "_extension_version_info");
71 	}
72 	new_extension = (zend_extension *) DL_FETCH_SYMBOL(handle, "zend_extension_entry");
73 	if (!new_extension) {
74 		new_extension = (zend_extension *) DL_FETCH_SYMBOL(handle, "_zend_extension_entry");
75 	}
76 	if (!extension_version_info || !new_extension) {
77 		fprintf(stderr, "%s doesn't appear to be a valid Zend extension\n", path);
78 /* See http://support.microsoft.com/kb/190351 */
79 #ifdef ZEND_WIN32
80 		fflush(stderr);
81 #endif
82 		DL_UNLOAD(handle);
83 		return FAILURE;
84 	}
85 
86 	/* allow extension to proclaim compatibility with any Zend version */
87 	if (extension_version_info->zend_extension_api_no != ZEND_EXTENSION_API_NO &&(!new_extension->api_no_check || new_extension->api_no_check(ZEND_EXTENSION_API_NO) != SUCCESS)) {
88 		if (extension_version_info->zend_extension_api_no > ZEND_EXTENSION_API_NO) {
89 			fprintf(stderr, "%s requires Zend Engine API version %d.\n"
90 					"The Zend Engine API version %d which is installed, is outdated.\n\n",
91 					new_extension->name,
92 					extension_version_info->zend_extension_api_no,
93 					ZEND_EXTENSION_API_NO);
94 /* See http://support.microsoft.com/kb/190351 */
95 #ifdef ZEND_WIN32
96 			fflush(stderr);
97 #endif
98 			DL_UNLOAD(handle);
99 			return FAILURE;
100 		} else if (extension_version_info->zend_extension_api_no < ZEND_EXTENSION_API_NO) {
101 			fprintf(stderr, "%s requires Zend Engine API version %d.\n"
102 					"The Zend Engine API version %d which is installed, is newer.\n"
103 					"Contact %s at %s for a later version of %s.\n\n",
104 					new_extension->name,
105 					extension_version_info->zend_extension_api_no,
106 					ZEND_EXTENSION_API_NO,
107 					new_extension->author,
108 					new_extension->URL,
109 					new_extension->name);
110 /* See http://support.microsoft.com/kb/190351 */
111 #ifdef ZEND_WIN32
112 			fflush(stderr);
113 #endif
114 			DL_UNLOAD(handle);
115 			return FAILURE;
116 		}
117 	} else if (strcmp(ZEND_EXTENSION_BUILD_ID, extension_version_info->build_id) &&
118 	           (!new_extension->build_id_check || new_extension->build_id_check(ZEND_EXTENSION_BUILD_ID) != SUCCESS)) {
119 		fprintf(stderr, "Cannot load %s - it was built with configuration %s, whereas running engine is %s\n",
120 					new_extension->name, extension_version_info->build_id, ZEND_EXTENSION_BUILD_ID);
121 /* See http://support.microsoft.com/kb/190351 */
122 #ifdef ZEND_WIN32
123 		fflush(stderr);
124 #endif
125 		DL_UNLOAD(handle);
126 		return FAILURE;
127 	} else if (zend_get_extension(new_extension->name)) {
128 		fprintf(stderr, "Cannot load %s - it was already loaded\n", new_extension->name);
129 /* See http://support.microsoft.com/kb/190351 */
130 #ifdef ZEND_WIN32
131 		fflush(stderr);
132 #endif
133 		DL_UNLOAD(handle);
134 		return FAILURE;
135 	}
136 
137 	zend_register_extension(new_extension, handle);
138 	return SUCCESS;
139 #else
140 	fprintf(stderr, "Extensions are not supported on this platform.\n");
141 /* See http://support.microsoft.com/kb/190351 */
142 #ifdef ZEND_WIN32
143 	fflush(stderr);
144 #endif
145 	return FAILURE;
146 #endif
147 }
148 
149 
zend_register_extension(zend_extension * new_extension,DL_HANDLE handle)150 void zend_register_extension(zend_extension *new_extension, DL_HANDLE handle)
151 {
152 #if ZEND_EXTENSIONS_SUPPORT
153 	zend_extension extension;
154 
155 	extension = *new_extension;
156 	extension.handle = handle;
157 
158 	zend_extension_dispatch_message(ZEND_EXTMSG_NEW_EXTENSION, &extension);
159 
160 	zend_llist_add_element(&zend_extensions, &extension);
161 
162 	if (extension.op_array_ctor) {
163 		zend_extension_flags |= ZEND_EXTENSIONS_HAVE_OP_ARRAY_CTOR;
164 	}
165 	if (extension.op_array_dtor) {
166 		zend_extension_flags |= ZEND_EXTENSIONS_HAVE_OP_ARRAY_DTOR;
167 	}
168 	if (extension.op_array_handler) {
169 		zend_extension_flags |= ZEND_EXTENSIONS_HAVE_OP_ARRAY_HANDLER;
170 	}
171 	if (extension.op_array_persist_calc) {
172 		zend_extension_flags |= ZEND_EXTENSIONS_HAVE_OP_ARRAY_PERSIST_CALC;
173 	}
174 	if (extension.op_array_persist) {
175 		zend_extension_flags |= ZEND_EXTENSIONS_HAVE_OP_ARRAY_PERSIST;
176 	}
177 	/*fprintf(stderr, "Loaded %s, version %s\n", extension.name, extension.version);*/
178 #endif
179 }
180 
181 
zend_extension_shutdown(zend_extension * extension)182 static void zend_extension_shutdown(zend_extension *extension)
183 {
184 #if ZEND_EXTENSIONS_SUPPORT
185 	if (extension->shutdown) {
186 		extension->shutdown(extension);
187 	}
188 #endif
189 }
190 
191 /* int return due to zend linked list API */
zend_extension_startup(zend_extension * extension)192 static int zend_extension_startup(zend_extension *extension)
193 {
194 #if ZEND_EXTENSIONS_SUPPORT
195 	if (extension->startup) {
196 		if (extension->startup(extension)!=SUCCESS) {
197 			return 1;
198 		}
199 		zend_append_version_info(extension);
200 	}
201 #endif
202 	return 0;
203 }
204 
205 
zend_startup_extensions_mechanism(void)206 void zend_startup_extensions_mechanism(void)
207 {
208 	/* Startup extensions mechanism */
209 	zend_llist_init(&zend_extensions, sizeof(zend_extension), (void (*)(void *)) zend_extension_dtor, 1);
210 	zend_op_array_extension_handles = 0;
211 	zend_internal_function_extension_handles = 0;
212 	last_resource_number = 0;
213 }
214 
215 
zend_startup_extensions(void)216 void zend_startup_extensions(void)
217 {
218 	zend_llist_apply_with_del(&zend_extensions, (int (*)(void *)) zend_extension_startup);
219 }
220 
221 
zend_shutdown_extensions(void)222 void zend_shutdown_extensions(void)
223 {
224 	zend_llist_apply(&zend_extensions, (llist_apply_func_t) zend_extension_shutdown);
225 	zend_llist_destroy(&zend_extensions);
226 }
227 
228 
zend_extension_dtor(zend_extension * extension)229 void zend_extension_dtor(zend_extension *extension)
230 {
231 #if ZEND_EXTENSIONS_SUPPORT && !ZEND_DEBUG
232 	if (extension->handle && !getenv("ZEND_DONT_UNLOAD_MODULES")) {
233 		DL_UNLOAD(extension->handle);
234 	}
235 #endif
236 }
237 
238 
zend_extension_message_dispatcher(const zend_extension * extension,int num_args,va_list args)239 static void zend_extension_message_dispatcher(const zend_extension *extension, int num_args, va_list args)
240 {
241 	int message;
242 	void *arg;
243 
244 	if (!extension->message_handler || num_args!=2) {
245 		return;
246 	}
247 	message = va_arg(args, int);
248 	arg = va_arg(args, void *);
249 	extension->message_handler(message, arg);
250 }
251 
252 
zend_extension_dispatch_message(int message,void * arg)253 ZEND_API void zend_extension_dispatch_message(int message, void *arg)
254 {
255 	zend_llist_apply_with_arguments(&zend_extensions, (llist_apply_with_args_func_t) zend_extension_message_dispatcher, 2, message, arg);
256 }
257 
258 
zend_get_resource_handle(const char * module_name)259 ZEND_API int zend_get_resource_handle(const char *module_name)
260 {
261 	if (last_resource_number<ZEND_MAX_RESERVED_RESOURCES) {
262 		zend_add_system_entropy(module_name, "zend_get_resource_handle", &last_resource_number, sizeof(int));
263 		return last_resource_number++;
264 	} else {
265 		return -1;
266 	}
267 }
268 
269 /**
270  * The handle returned by this function can be used with
271  * `ZEND_OP_ARRAY_EXTENSION(op_array, handle)`.
272  *
273  * The extension slot has been available since PHP 7.4 on user functions and
274  * has been available since PHP 8.2 on internal functions.
275  *
276  * # Safety
277  * The extension slot made available by calling this function is initialized on
278  * the first call made to the function in that request. If you need to
279  * initialize it before this point, call `zend_init_func_run_time_cache`.
280  *
281  * The function cache slots are not available if the function is a trampoline,
282  * which can be checked with something like:
283  *
284  *     if (fbc->type == ZEND_USER_FUNCTION
285  *         && !(fbc->op_array.fn_flags & ZEND_ACC_CALL_VIA_TRAMPOLINE)
286  *     ) {
287  *         // Use ZEND_OP_ARRAY_EXTENSION somehow
288  *     }
289  */
zend_get_op_array_extension_handle(const char * module_name)290 ZEND_API int zend_get_op_array_extension_handle(const char *module_name)
291 {
292 	int handle = zend_op_array_extension_handles++;
293 	zend_add_system_entropy(module_name, "zend_get_op_array_extension_handle", &zend_op_array_extension_handles, sizeof(int));
294 	return handle;
295 }
296 
297 /** See zend_get_op_array_extension_handle for important usage information. */
zend_get_op_array_extension_handles(const char * module_name,int handles)298 ZEND_API int zend_get_op_array_extension_handles(const char *module_name, int handles)
299 {
300 	int handle = zend_op_array_extension_handles;
301 	zend_op_array_extension_handles += handles;
302 	zend_add_system_entropy(module_name, "zend_get_op_array_extension_handle", &zend_op_array_extension_handles, sizeof(int));
303 	return handle;
304 }
305 
zend_get_internal_function_extension_handle(const char * module_name)306 ZEND_API int zend_get_internal_function_extension_handle(const char *module_name)
307 {
308 	int handle = zend_internal_function_extension_handles++;
309 	zend_add_system_entropy(module_name, "zend_get_internal_function_extension_handle", &zend_internal_function_extension_handles, sizeof(int));
310 	return handle;
311 }
312 
zend_get_internal_function_extension_handles(const char * module_name,int handles)313 ZEND_API int zend_get_internal_function_extension_handles(const char *module_name, int handles)
314 {
315 	int handle = zend_internal_function_extension_handles;
316 	zend_internal_function_extension_handles += handles;
317 	zend_add_system_entropy(module_name, "zend_get_internal_function_extension_handle", &zend_internal_function_extension_handles, sizeof(int));
318 	return handle;
319 }
320 
zend_internal_run_time_cache_reserved_size(void)321 ZEND_API size_t zend_internal_run_time_cache_reserved_size(void) {
322 	return zend_internal_function_extension_handles * sizeof(void *);
323 }
324 
zend_init_internal_run_time_cache(void)325 ZEND_API void zend_init_internal_run_time_cache(void) {
326 	size_t rt_size = zend_internal_run_time_cache_reserved_size();
327 	if (rt_size) {
328 		size_t functions = zend_hash_num_elements(CG(function_table));
329 		zend_class_entry *ce;
330 		ZEND_HASH_MAP_FOREACH_PTR(CG(class_table), ce) {
331 			functions += zend_hash_num_elements(&ce->function_table);
332 		} ZEND_HASH_FOREACH_END();
333 
334 		size_t alloc_size = functions * rt_size;
335 		char *ptr = pemalloc(alloc_size, 1);
336 
337 		CG(internal_run_time_cache) = ptr;
338 		CG(internal_run_time_cache_size) = alloc_size;
339 
340 		zend_internal_function *zif;
341 		ZEND_HASH_MAP_FOREACH_PTR(CG(function_table), zif) {
342 			if (!ZEND_USER_CODE(zif->type) && ZEND_MAP_PTR_GET(zif->run_time_cache) == NULL) {
343 				ZEND_MAP_PTR_SET(zif->run_time_cache, (void *)ptr);
344 				ptr += rt_size;
345 			}
346 		} ZEND_HASH_FOREACH_END();
347 		ZEND_HASH_MAP_FOREACH_PTR(CG(class_table), ce) {
348 			ZEND_HASH_MAP_FOREACH_PTR(&ce->function_table, zif) {
349 				if (!ZEND_USER_CODE(zif->type) && ZEND_MAP_PTR_GET(zif->run_time_cache) == NULL) {
350 					ZEND_MAP_PTR_SET(zif->run_time_cache, (void *)ptr);
351 					ptr += rt_size;
352 				}
353 			} ZEND_HASH_FOREACH_END();
354 		} ZEND_HASH_FOREACH_END();
355 	}
356 }
357 
zend_reset_internal_run_time_cache(void)358 ZEND_API void zend_reset_internal_run_time_cache(void) {
359 	if (CG(internal_run_time_cache)) {
360 		memset(CG(internal_run_time_cache), 0, CG(internal_run_time_cache_size));
361 	}
362 }
363 
zend_get_extension(const char * extension_name)364 ZEND_API zend_extension *zend_get_extension(const char *extension_name)
365 {
366 	zend_llist_element *element;
367 
368 	for (element = zend_extensions.head; element; element = element->next) {
369 		zend_extension *extension = (zend_extension *) element->data;
370 
371 		if (!strcmp(extension->name, extension_name)) {
372 			return extension;
373 		}
374 	}
375 	return NULL;
376 }
377 
378 typedef struct _zend_extension_persist_data {
379 	zend_op_array *op_array;
380 	size_t         size;
381 	char          *mem;
382 } zend_extension_persist_data;
383 
zend_extension_op_array_persist_calc_handler(zend_extension * extension,zend_extension_persist_data * data)384 static void zend_extension_op_array_persist_calc_handler(zend_extension *extension, zend_extension_persist_data *data)
385 {
386 	if (extension->op_array_persist_calc) {
387 		data->size += extension->op_array_persist_calc(data->op_array);
388 	}
389 }
390 
zend_extension_op_array_persist_handler(zend_extension * extension,zend_extension_persist_data * data)391 static void zend_extension_op_array_persist_handler(zend_extension *extension, zend_extension_persist_data *data)
392 {
393 	if (extension->op_array_persist) {
394 		size_t size = extension->op_array_persist(data->op_array, data->mem);
395 		if (size) {
396 			data->mem = (void*)((char*)data->mem + size);
397 			data->size += size;
398 		}
399 	}
400 }
401 
zend_extensions_op_array_persist_calc(zend_op_array * op_array)402 ZEND_API size_t zend_extensions_op_array_persist_calc(zend_op_array *op_array)
403 {
404 	if (zend_extension_flags & ZEND_EXTENSIONS_HAVE_OP_ARRAY_PERSIST_CALC) {
405 		zend_extension_persist_data data;
406 
407 		data.op_array = op_array;
408 		data.size = 0;
409 		data.mem  = NULL;
410 		zend_llist_apply_with_argument(&zend_extensions, (llist_apply_with_arg_func_t) zend_extension_op_array_persist_calc_handler, &data);
411 		return data.size;
412 	}
413 	return 0;
414 }
415 
zend_extensions_op_array_persist(zend_op_array * op_array,void * mem)416 ZEND_API size_t zend_extensions_op_array_persist(zend_op_array *op_array, void *mem)
417 {
418 	if (zend_extension_flags & ZEND_EXTENSIONS_HAVE_OP_ARRAY_PERSIST) {
419 		zend_extension_persist_data data;
420 
421 		data.op_array = op_array;
422 		data.size = 0;
423 		data.mem  = mem;
424 		zend_llist_apply_with_argument(&zend_extensions, (llist_apply_with_arg_func_t) zend_extension_op_array_persist_handler, &data);
425 		return data.size;
426 	}
427 	return 0;
428 }
429