| /* Licensed to the Apache Software Foundation (ASF) under one or more |
| * contributor license agreements. See the NOTICE file distributed with |
| * this work for additional information regarding copyright ownership. |
| * The ASF licenses this file to You 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. |
| */ |
| |
| /* |
| * This module is used to load Apache modules at runtime. This means that the |
| * server functionality can be extended without recompiling and even without |
| * taking the server down at all. Only a HUP or USR1 signal needs to be send |
| * to the server to reload the dynamically loaded modules. |
| * |
| * To use, you'll first need to build your module as a shared library, then |
| * update your configuration (httpd.conf) to get the Apache core to load the |
| * module at start-up. |
| * |
| * The easiest way to build a module as a shared library is to use the |
| * `SharedModule' command in the Configuration file, instead of `AddModule'. |
| * You should also change the file extension from `.o' to `.so'. So, for |
| * example, to build the status module as a shared library edit Configuration |
| * and change |
| * AddModule modules/standard/mod_status.o |
| * to |
| * SharedModule modules/standard/mod_status.so |
| * |
| * Run Configure and make. Now Apache's httpd binary will _not_ include |
| * mod_status. Instead a shared object called mod_status.so will be build, in |
| * the modules/standard directory. You can build most of the modules as shared |
| * libraries like this. |
| * |
| * To use the shared module, move the .so file(s) into an appropriate |
| * directory. You might like to create a directory called "modules" under you |
| * server root for this (e.g. /usr/local/httpd/modules). |
| * |
| * Then edit your conf/httpd.conf file, and add LoadModule lines. For |
| * example |
| * LoadModule status_module modules/mod_status.so |
| * |
| * The first argument is the module's structure name (look at the end of the |
| * module source to find this). The second option is the path to the module |
| * file, relative to the server root. Put these directives right at the top |
| * of your httpd.conf file. |
| * |
| * Now you can start Apache. A message will be logged at "debug" level to your |
| * error_log to confirm that the module(s) are loaded (use "LogLevel debug" |
| * directive to get these log messages). |
| * |
| * If you edit the LoadModule directives while the server is live you can get |
| * Apache to re-load the modules by sending it a HUP or USR1 signal as normal. |
| * You can use this to dynamically change the capability of your server |
| * without bringing it down. |
| * |
| * Because currently there is only limited built-in support in the Configure |
| * script for creating the shared library files (`.so'), please consult your |
| * vendors cc(1), ld(1) and dlopen(3) manpages to find out the appropriate |
| * compiler and linker flags and insert them manually into the Configuration |
| * file under CFLAGS_SHLIB, LDFLAGS_SHLIB and LDFLAGS_SHLIB_EXPORT. |
| * |
| * If you still have problems figuring out the flags both try the paper |
| * http://developer.netscape.com/library/documentation/enterprise |
| * /unix/svrplug.htm#1013807 |
| * or install a Perl 5 interpreter on your platform and then run the command |
| * |
| * $ perl -V:usedl -V:ccdlflags -V:cccdlflags -V:lddlflags |
| * |
| * This gives you what type of dynamic loading Perl 5 uses on your platform |
| * and which compiler and linker flags Perl 5 uses to create the shared object |
| * files. |
| * |
| * Another location where you can find useful hints is the `ltconfig' script |
| * of the GNU libtool 1.2 package. Search for your platform name inside the |
| * various "case" constructs. |
| * |
| */ |
| |
| |
| #define CORE_PRIVATE |
| #include "httpd.h" |
| #include "http_config.h" |
| #include "http_log.h" |
| |
| module MODULE_VAR_EXPORT so_module; |
| |
| |
| /* |
| * Server configuration to keep track of actually |
| * loaded modules and the corresponding module name. |
| */ |
| |
| typedef struct moduleinfo { |
| char *name; |
| module *modp; |
| } moduleinfo; |
| |
| typedef struct so_server_conf { |
| array_header *loaded_modules; |
| } so_server_conf; |
| |
| static void *so_sconf_create(pool *p, server_rec *s) |
| { |
| so_server_conf *soc; |
| |
| soc = (so_server_conf *)ap_pcalloc(p, sizeof(so_server_conf)); |
| soc->loaded_modules = ap_make_array(p, DYNAMIC_MODULE_LIMIT, |
| sizeof(moduleinfo)); |
| #ifndef NO_DLOPEN |
| ap_os_dso_init(); |
| #endif |
| |
| return (void *)soc; |
| } |
| |
| #ifndef NO_DLOPEN |
| |
| /* |
| * This is the cleanup for a loaded shared object. It unloads the module. |
| * This is called as a cleanup function from the core. |
| */ |
| |
| static void unload_module(moduleinfo *modi) |
| { |
| /* only unload if module information is still existing */ |
| if (modi->modp == NULL) |
| return; |
| |
| /* remove the module pointer from the core structure */ |
| ap_remove_loaded_module(modi->modp); |
| |
| /* unload the module space itself */ |
| #ifdef NETWARE |
| ap_os_dso_unsym((ap_os_dso_handle_t)modi->modp->dynamic_load_handle, modi->name); |
| #endif |
| ap_os_dso_unload((ap_os_dso_handle_t)modi->modp->dynamic_load_handle); |
| |
| /* destroy the module information */ |
| modi->modp = NULL; |
| modi->name = NULL; |
| } |
| |
| /* |
| * This is the cleanup routine for files loaded by |
| * load_file(). Unfortunately we don't keep a record of the filename |
| * that was loaded, so we can't report the unload for debug purposes |
| * or include the filename in error message. |
| */ |
| |
| static void unload_file(void *handle) |
| { |
| ap_os_dso_unload((ap_os_dso_handle_t)handle); |
| } |
| |
| /* |
| * This is called for the directive LoadModule and actually loads |
| * a shared object file into the address space of the server process. |
| */ |
| |
| static const char *load_module(cmd_parms *cmd, void *dummy, |
| char *modname, char *filename) |
| { |
| ap_os_dso_handle_t modhandle; |
| module *modp; |
| const char *szModuleFile=ap_server_root_relative(cmd->pool, filename); |
| so_server_conf *sconf; |
| moduleinfo *modi; |
| moduleinfo *modie; |
| int i; |
| |
| const char *err = ap_check_cmd_context(cmd, GLOBAL_ONLY); |
| if (err != NULL) { |
| return err; |
| } |
| |
| /* |
| * check for already existing module |
| * If it already exists, we have nothing to do |
| * Check both dynamically-loaded modules and statically-linked modules. |
| */ |
| sconf = (so_server_conf *)ap_get_module_config(cmd->server->module_config, |
| &so_module); |
| modie = (moduleinfo *)sconf->loaded_modules->elts; |
| for (i = 0; i < sconf->loaded_modules->nelts; i++) { |
| modi = &modie[i]; |
| if (modi->name != NULL && strcmp(modi->name, modname) == 0) { |
| ap_log_error(APLOG_MARK, APLOG_WARNING|APLOG_NOERRNO, cmd->server, |
| "module %s is already loaded, skipping", modname); |
| return NULL; |
| } |
| } |
| |
| for (i = 0; ap_preloaded_modules[i]; i++) { |
| const char *preload_name; |
| size_t preload_len; |
| size_t thismod_len; |
| |
| modp = ap_preloaded_modules[i]; |
| |
| /* make sure we're comparing apples with apples |
| * make sure name of preloaded module is mod_FOO.c |
| * make sure name of structure being loaded is FOO_module |
| */ |
| |
| if (memcmp(modp->name, "mod_", 4)) { |
| continue; |
| } |
| |
| preload_name = modp->name + strlen("mod_"); |
| preload_len = strlen(preload_name) - 2; |
| |
| if (strlen(modname) <= strlen("_module")) { |
| continue; |
| } |
| thismod_len = strlen(modname) - strlen("_module"); |
| if (strcmp(modname + thismod_len, "_module")) { |
| continue; |
| } |
| |
| if (thismod_len != preload_len) { |
| continue; |
| } |
| |
| if (!memcmp(modname, preload_name, preload_len)) { |
| return ap_pstrcat(cmd->pool, "module ", modname, |
| " is built-in and can't be loaded", |
| NULL); |
| } |
| } |
| |
| modi = ap_push_array(sconf->loaded_modules); |
| modi->name = modname; |
| |
| /* |
| * Load the file into the Apache address space |
| */ |
| if (!(modhandle = ap_os_dso_load(szModuleFile))) { |
| const char *my_error = ap_os_dso_error(); |
| return ap_pstrcat (cmd->pool, "Cannot load ", szModuleFile, |
| " into server: ", |
| my_error ? my_error : "(reason unknown)", |
| NULL); |
| } |
| ap_log_error(APLOG_MARK, APLOG_DEBUG|APLOG_NOERRNO, NULL, |
| "loaded module %s", modname); |
| |
| /* |
| * Retrieve the pointer to the module structure through the module name: |
| * First with the hidden variant (prefix `AP_') and then with the plain |
| * symbol name. |
| */ |
| if (!(modp = (module *)(ap_os_dso_sym(modhandle, modname)))) { |
| return ap_pstrcat(cmd->pool, "Can't locate API module structure `", modname, |
| "' in file ", szModuleFile, ": ", ap_os_dso_error(), NULL); |
| } |
| modi->modp = modp; |
| modp->dynamic_load_handle = (void *)modhandle; |
| |
| /* |
| * Make sure the found module structure is really a module structure |
| * |
| */ |
| if (modp->magic != MODULE_MAGIC_COOKIE) { |
| return ap_pstrcat(cmd->pool, "API module structure `", modname, |
| "' in file ", szModuleFile, " is garbled -" |
| " perhaps this is not an Apache module DSO?", NULL); |
| } |
| |
| /* |
| * Add this module to the Apache core structures |
| */ |
| ap_add_loaded_module(modp); |
| |
| /* |
| * Register a cleanup in the config pool (normally pconf). When |
| * we do a restart (or shutdown) this cleanup will cause the |
| * shared object to be unloaded. |
| */ |
| ap_register_cleanup(cmd->pool, modi, |
| (void (*)(void*))unload_module, ap_null_cleanup); |
| |
| /* |
| * Finally we need to run the configuration process for the module |
| */ |
| ap_single_module_configure(cmd->pool, cmd->server, modp); |
| |
| return NULL; |
| } |
| |
| /* |
| * This implements the LoadFile directive and loads an arbitrary |
| * shared object file into the adress space of the server process. |
| */ |
| |
| static const char *load_file(cmd_parms *cmd, void *dummy, char *filename) |
| { |
| ap_os_dso_handle_t handle; |
| char *file; |
| |
| const char *err = ap_check_cmd_context(cmd, GLOBAL_ONLY); |
| if (err != NULL) { |
| return err; |
| } |
| |
| file = ap_server_root_relative(cmd->pool, filename); |
| |
| if (!(handle = ap_os_dso_load(file))) { |
| const char *my_error = ap_os_dso_error(); |
| return ap_pstrcat (cmd->pool, "Cannot load ", filename, |
| " into server:", |
| my_error ? my_error : "(reason unknown)", |
| NULL); |
| } |
| |
| ap_log_error(APLOG_MARK, APLOG_DEBUG|APLOG_NOERRNO, NULL, |
| "loaded file %s", filename); |
| |
| ap_register_cleanup(cmd->pool, (void *)handle, unload_file, ap_null_cleanup); |
| |
| return NULL; |
| } |
| |
| #else /* not NO_DLOPEN */ |
| |
| static const char *load_file(cmd_parms *cmd, void *dummy, char *filename) |
| { |
| fprintf(stderr, "WARNING: LoadFile not supported on this platform\n"); |
| return NULL; |
| } |
| |
| static const char *load_module(cmd_parms *cmd, void *dummy, |
| char *modname, char *filename) |
| { |
| fprintf(stderr, "WARNING: LoadModule not supported on this platform\n"); |
| return NULL; |
| } |
| |
| #endif /* NO_DLOPEN */ |
| |
| static const command_rec so_cmds[] = { |
| { "LoadModule", load_module, NULL, RSRC_CONF, TAKE2, |
| "a module name and the name of a shared object file to load it from"}, |
| { "LoadFile", load_file, NULL, RSRC_CONF, ITERATE, |
| "shared object file or library to load into the server at runtime"}, |
| { NULL } |
| }; |
| |
| module MODULE_VAR_EXPORT so_module = { |
| STANDARD_MODULE_STUFF, |
| NULL, /* initializer */ |
| NULL, /* create per-dir config */ |
| NULL, /* merge per-dir config */ |
| so_sconf_create, /* server config */ |
| NULL, /* merge server config */ |
| so_cmds, /* command table */ |
| NULL, /* handlers */ |
| NULL, /* filename translation */ |
| NULL, /* check_user_id */ |
| NULL, /* check auth */ |
| NULL, /* check access */ |
| NULL, /* type_checker */ |
| NULL, /* fixer_upper */ |
| NULL, /* logger */ |
| NULL, /* header parser */ |
| NULL, /* child_init */ |
| NULL, /* child_exit */ |
| NULL /* post read-request */ |
| }; |