php-src/ext/standard/dl.c
Christoph M. Becker 3e33e1e86d Check linker compatibility directly from HMODULE
Checking the linker compatibility with extranous `ImageLoad()` calls is
possible, but unnecessary, since the modules are either already loaded
or loaded shortly afterwards, so that we can get the required
information directly from the module handles.  And actually, doing
`ImageLoad()` as well as `LoadLibrary()` leaves a tiny room for a race
condition, because both functions will lookup the module in the search
path, so there is no *guarantee* that both are dealing with the same
module.  Dropping the `ImageLoad()` calls also has the advantage to no
longer face the issue reported in bug #79557.  A very minor additional
advantage is that we no longer have to link against Imagehlp.dll.

Furthermore, there is no need to check for CRT compatibility multiple
times, so we can simplify the signature of `php_win32_crt_compatible`,
and at the same time clean up main.c a bit.

These changes require to change the signature of the exported
`php_win32_image_compatible` and `php_win32_crt_compatible` functions,
which now expect a `HMODULE` and nothing, respectively, instead of the
module name.
2020-09-21 16:25:31 +02:00

284 lines
8.2 KiB
C

/*
+----------------------------------------------------------------------+
| Copyright (c) The PHP Group |
+----------------------------------------------------------------------+
| This source file is subject to version 3.01 of the PHP license, |
| that is bundled with this package in the file LICENSE, and is |
| available through the world-wide-web at the following url: |
| http://www.php.net/license/3_01.txt |
| If you did not receive a copy of the PHP license and are unable to |
| obtain it through the world-wide-web, please send a note to |
| license@php.net so we can mail you a copy immediately. |
+----------------------------------------------------------------------+
| Authors: Brian Schaffner <brian@tool.net> |
| Shane Caraveo <shane@caraveo.com> |
| Zeev Suraski <zeev@php.net> |
+----------------------------------------------------------------------+
*/
#include "php.h"
#include "dl.h"
#include "php_globals.h"
#include "php_ini.h"
#include "ext/standard/info.h"
#include "SAPI.h"
#if defined(HAVE_LIBDL)
#include <stdlib.h>
#include <stdio.h>
#include <string.h>
#ifdef PHP_WIN32
#include "win32/param.h"
#include "win32/winutil.h"
#define GET_DL_ERROR() php_win_err()
#else
#include <sys/param.h>
#define GET_DL_ERROR() DL_ERROR()
#endif
#endif /* defined(HAVE_LIBDL) */
/* {{{ Load a PHP extension at runtime */
PHPAPI PHP_FUNCTION(dl)
{
char *filename;
size_t filename_len;
ZEND_PARSE_PARAMETERS_START(1, 1)
Z_PARAM_STRING(filename, filename_len)
ZEND_PARSE_PARAMETERS_END();
if (!PG(enable_dl)) {
php_error_docref(NULL, E_WARNING, "Dynamically loaded extensions aren't enabled");
RETURN_FALSE;
}
if (filename_len >= MAXPATHLEN) {
php_error_docref(NULL, E_WARNING, "Filename exceeds the maximum allowed length of %d characters", MAXPATHLEN);
RETURN_FALSE;
}
php_dl(filename, MODULE_TEMPORARY, return_value, 0);
if (Z_TYPE_P(return_value) == IS_TRUE) {
EG(full_tables_cleanup) = 1;
}
}
/* }}} */
#if defined(HAVE_LIBDL)
/* {{{ php_load_shlib */
PHPAPI void *php_load_shlib(const char *path, char **errp)
{
void *handle;
char *err;
handle = DL_LOAD(path);
if (!handle) {
err = GET_DL_ERROR();
#ifdef PHP_WIN32
if (err && (*err)) {
size_t i = strlen(err);
(*errp)=estrdup(err);
php_win32_error_msg_free(err);
while (i > 0 && isspace((*errp)[i-1])) { (*errp)[i-1] = '\0'; i--; }
} else {
(*errp) = estrdup("<No message>");
}
#else
(*errp) = estrdup(err);
GET_DL_ERROR(); /* free the buffer storing the error */
#endif
}
return handle;
}
/* }}} */
/* {{{ php_load_extension */
PHPAPI int php_load_extension(const char *filename, int type, int start_now)
{
void *handle;
char *libpath;
zend_module_entry *module_entry;
zend_module_entry *(*get_module)(void);
int error_type, slash_suffix = 0;
char *extension_dir;
char *err1, *err2;
if (type == MODULE_PERSISTENT) {
extension_dir = INI_STR("extension_dir");
} else {
extension_dir = PG(extension_dir);
}
if (type == MODULE_TEMPORARY) {
error_type = E_WARNING;
} else {
error_type = E_CORE_WARNING;
}
/* Check if passed filename contains directory separators */
if (strchr(filename, '/') != NULL || strchr(filename, DEFAULT_SLASH) != NULL) {
/* Passing modules with full path is not supported for dynamically loaded extensions */
if (type == MODULE_TEMPORARY) {
php_error_docref(NULL, E_WARNING, "Temporary module name should contain only filename");
return FAILURE;
}
libpath = estrdup(filename);
} else if (extension_dir && extension_dir[0]) {
slash_suffix = IS_SLASH(extension_dir[strlen(extension_dir)-1]);
/* Try as filename first */
if (slash_suffix) {
spprintf(&libpath, 0, "%s%s", extension_dir, filename); /* SAFE */
} else {
spprintf(&libpath, 0, "%s%c%s", extension_dir, DEFAULT_SLASH, filename); /* SAFE */
}
} else {
return FAILURE; /* Not full path given or extension_dir is not set */
}
handle = php_load_shlib(libpath, &err1);
if (!handle) {
/* Now, consider 'filename' as extension name and build file name */
char *orig_libpath = libpath;
if (slash_suffix) {
spprintf(&libpath, 0, "%s" PHP_SHLIB_EXT_PREFIX "%s." PHP_SHLIB_SUFFIX, extension_dir, filename); /* SAFE */
} else {
spprintf(&libpath, 0, "%s%c" PHP_SHLIB_EXT_PREFIX "%s." PHP_SHLIB_SUFFIX, extension_dir, DEFAULT_SLASH, filename); /* SAFE */
}
handle = php_load_shlib(libpath, &err2);
if (!handle) {
php_error_docref(NULL, error_type, "Unable to load dynamic library '%s' (tried: %s (%s), %s (%s))",
filename, orig_libpath, err1, libpath, err2);
efree(orig_libpath);
efree(err1);
efree(libpath);
efree(err2);
return FAILURE;
}
efree(orig_libpath);
efree(err1);
}
efree(libpath);
#ifdef PHP_WIN32
if (!php_win32_image_compatible(handle, &err1)) {
php_error_docref(NULL, error_type, err1);
efree(err1);
DL_UNLOAD(handle);
return FAILURE;
}
#endif
get_module = (zend_module_entry *(*)(void)) DL_FETCH_SYMBOL(handle, "get_module");
/* Some OS prepend _ to symbol names while their dynamic linker
* does not do that automatically. Thus we check manually for
* _get_module. */
if (!get_module) {
get_module = (zend_module_entry *(*)(void)) DL_FETCH_SYMBOL(handle, "_get_module");
}
if (!get_module) {
if (DL_FETCH_SYMBOL(handle, "zend_extension_entry") || DL_FETCH_SYMBOL(handle, "_zend_extension_entry")) {
DL_UNLOAD(handle);
php_error_docref(NULL, error_type, "Invalid library (appears to be a Zend Extension, try loading using zend_extension=%s from php.ini)", filename);
return FAILURE;
}
DL_UNLOAD(handle);
php_error_docref(NULL, error_type, "Invalid library (maybe not a PHP library) '%s'", filename);
return FAILURE;
}
module_entry = get_module();
if (module_entry->zend_api != ZEND_MODULE_API_NO) {
php_error_docref(NULL, error_type,
"%s: Unable to initialize module\n"
"Module compiled with module API=%d\n"
"PHP compiled with module API=%d\n"
"These options need to match\n",
module_entry->name, module_entry->zend_api, ZEND_MODULE_API_NO);
DL_UNLOAD(handle);
return FAILURE;
}
if(strcmp(module_entry->build_id, ZEND_MODULE_BUILD_ID)) {
php_error_docref(NULL, error_type,
"%s: Unable to initialize module\n"
"Module compiled with build ID=%s\n"
"PHP compiled with build ID=%s\n"
"These options need to match\n",
module_entry->name, module_entry->build_id, ZEND_MODULE_BUILD_ID);
DL_UNLOAD(handle);
return FAILURE;
}
module_entry->type = type;
module_entry->module_number = zend_next_free_module();
module_entry->handle = handle;
if ((module_entry = zend_register_module_ex(module_entry)) == NULL) {
DL_UNLOAD(handle);
return FAILURE;
}
if ((type == MODULE_TEMPORARY || start_now) && zend_startup_module_ex(module_entry) == FAILURE) {
DL_UNLOAD(handle);
return FAILURE;
}
if ((type == MODULE_TEMPORARY || start_now) && module_entry->request_startup_func) {
if (module_entry->request_startup_func(type, module_entry->module_number) == FAILURE) {
php_error_docref(NULL, error_type, "Unable to initialize module '%s'", module_entry->name);
DL_UNLOAD(handle);
return FAILURE;
}
}
return SUCCESS;
}
/* }}} */
#else
static void php_dl_error(const char *filename)
{
php_error_docref(NULL, E_WARNING, "Cannot dynamically load %s - dynamic modules are not supported", filename);
}
PHPAPI void *php_load_shlib(const char *path, char **errp)
{
php_dl_error(filename);
(*errp) = estrdup("No DL support");
}
PHPAPI int php_load_extension(const char *filename, int type, int start_now)
{
php_dl_error(filename);
return FAILURE;
}
#endif
/* {{{ php_dl */
PHPAPI void php_dl(const char *file, int type, zval *return_value, int start_now)
{
/* Load extension */
if (php_load_extension(file, type, start_now) == FAILURE) {
RETVAL_FALSE;
} else {
RETVAL_TRUE;
}
}
/* }}} */
PHP_MINFO_FUNCTION(dl)
{
#if defined(HAVE_LIBDL)
#define PHP_DL_SUPPORT_STATUS "enabled"
#else
#define PHP_DL_SUPPORT_STATUS "unavailable"
#endif
php_info_print_table_row(2, "Dynamic Library Support", PHP_DL_SUPPORT_STATUS);
}