external/bsd/openldap/dist/servers/slapd/module.c

   1 /* $OpenLDAP: pkg/ldap/servers/slapd/module.c,v 1.29.2.3 2008/02/11 23:26:44 kurt Exp $ */
   2 /* This work is part of OpenLDAP Software <http://www.openldap.org/>.
   3  *
   4  * Copyright 1998-2008 The OpenLDAP Foundation.
   5  * All rights reserved.
   6  *
   7  * Redistribution and use in source and binary forms, with or without
   8  * modification, are permitted only as authorized by the OpenLDAP
   9  * Public License.
  10  *
  11  * A copy of this license is available in the file LICENSE in the
  12  * top-level directory of the distribution or, alternatively, at
  13  * <http://www.OpenLDAP.org/license.html>.
  14  */
  15
  16 #include "portable.h"
  17 #include <stdio.h>
  18 #include "slap.h"
  19
  20 #ifdef SLAPD_MODULES
  21
  22 #include <ltdl.h>
  23
  24 typedef int (*MODULE_INIT_FN)(
  25         int argc,
  26         char *argv[]);
  27 typedef int (*MODULE_LOAD_FN)(
  28         const void *module,
  29         const char *filename);
  30 typedef int (*MODULE_TERM_FN)(void);
  31
  32
  33 struct module_regtable_t {
  34         char *type;
  35         MODULE_LOAD_FN proc;
  36 } module_regtable[] = {
  37                 { "null", load_null_module },
  38 #ifdef SLAPD_EXTERNAL_EXTENSIONS
  39                 { "extension", load_extop_module },
  40 #endif
  41                 { NULL, NULL }
  42 };
  43
  44 typedef struct module_loaded_t {
  45         struct module_loaded_t *next;
  46         lt_dlhandle lib;
  47         char name[1];
  48 } module_loaded_t;
  49
  50 module_loaded_t *module_list = NULL;
  51
  52 static int module_int_unload (module_loaded_t *module);
  53
  54 #ifdef HAVE_EBCDIC
  55 static char ebuf[BUFSIZ];
  56 #endif
  57
  58 int module_init (void)
  59 {
  60         if (lt_dlinit()) {
  61                 const char *error = lt_dlerror();
  62 #ifdef HAVE_EBCDIC
  63                 strcpy( ebuf, error );
  64                 __etoa( ebuf );
  65                 error = ebuf;
  66 #endif
  67                 Debug(LDAP_DEBUG_ANY, "lt_dlinit failed: %s\n", error, 0, 0);
  68
  69                 return -1;
  70         }
  71
  72         return module_path( LDAP_MODULEDIR );
  73 }
  74
  75 int module_kill (void)
  76 {
  77         /* unload all modules before shutdown */
  78         while (module_list != NULL) {
  79                 module_int_unload(module_list);
  80         }
  81
  82         if (lt_dlexit()) {
  83                 const char *error = lt_dlerror();
  84 #ifdef HAVE_EBCDIC
  85                 strcpy( ebuf, error );
  86                 __etoa( ebuf );
  87                 error = ebuf;
  88 #endif
  89                 Debug(LDAP_DEBUG_ANY, "lt_dlexit failed: %s\n", error, 0, 0);
  90
  91                 return -1;
  92         }
  93         return 0;
  94 }
  95
  96 void * module_handle( const char *file_name )
  97 {
  98         module_loaded_t *module;
  99
 100         for ( module = module_list; module; module= module->next ) {
 101                 if ( !strcmp( module->name, file_name )) {
 102                         return module;
 103                 }
 104         }
 105         return NULL;
 106 }
 107
 108 int module_unload( const char *file_name )
 109 {
 110         module_loaded_t *module;
 111
 112         module = module_handle( file_name );
 113         if ( module ) {
 114                 module_int_unload( module );
 115                 return 0;
 116         }
 117         return -1;      /* not found */
 118 }
 119
 120 int module_load(const char* file_name, int argc, char *argv[])
 121 {
 122         module_loaded_t *module = NULL;
 123         const char *error;
 124         int rc;
 125         MODULE_INIT_FN initialize;
 126 #ifdef HAVE_EBCDIC
 127 #define file    ebuf
 128 #else
 129 #define file    file_name
 130 #endif
 131
 132         module = (module_loaded_t *)ch_calloc(1, sizeof(module_loaded_t) +
 133                 strlen(file_name));
 134         if (module == NULL) {
 135                 Debug(LDAP_DEBUG_ANY, "module_load failed: (%s) out of memory\n", file_name,
 136                         0, 0);
 137
 138                 return -1;
 139         }
 140         strcpy( module->name, file_name );
 141
 142 #ifdef HAVE_EBCDIC
 143         strcpy( file, file_name );
 144         __atoe( file );
 145 #endif
 146         /*
 147          * The result of lt_dlerror(), when called, must be cached prior
 148          * to calling Debug. This is because Debug is a macro that expands
 149          * into multiple function calls.
 150          */
 151         if ((module->lib = lt_dlopenext(file)) == NULL) {
 152                 error = lt_dlerror();
 153 #ifdef HAVE_EBCDIC
 154                 strcpy( ebuf, error );
 155                 __etoa( ebuf );
 156                 error = ebuf;
 157 #endif
 158                 Debug(LDAP_DEBUG_ANY, "lt_dlopenext failed: (%s) %s\n", file_name,
 159                         error, 0);
 160
 161                 ch_free(module);
 162                 return -1;
 163         }
 164
 165         Debug(LDAP_DEBUG_CONFIG, "loaded module %s\n", file_name, 0, 0);
 166
 167
 168 #ifdef HAVE_EBCDIC
 169 #pragma convlit(suspend)
 170 #endif
 171         if ((initialize = lt_dlsym(module->lib, "init_module")) == NULL) {
 172 #ifdef HAVE_EBCDIC
 173 #pragma convlit(resume)
 174 #endif
 175                 Debug(LDAP_DEBUG_CONFIG, "module %s: no init_module() function found\n",
 176                         file_name, 0, 0);
 177
 178                 lt_dlclose(module->lib);
 179                 ch_free(module);
 180                 return -1;
 181         }
 182
 183         /* The imported init_module() routine passes back the type of
 184          * module (i.e., which part of slapd it should be hooked into)
 185          * or -1 for error.  If it passes back 0, then you get the
 186          * old behavior (i.e., the library is loaded and not hooked
 187          * into anything).
 188          *
 189          * It might be better if the conf file could specify the type
 190          * of module.  That way, a single module could support multiple
 191          * type of hooks. This could be done by using something like:
 192          *
 193          *    moduleload extension /usr/local/openldap/whatever.so
 194          *
 195          * then we'd search through module_regtable for a matching
 196          * module type, and hook in there.
 197          */
 198         rc = initialize(argc, argv);
 199         if (rc == -1) {
 200                 Debug(LDAP_DEBUG_CONFIG, "module %s: init_module() failed\n",
 201                         file_name, 0, 0);
 202
 203                 lt_dlclose(module->lib);
 204                 ch_free(module);
 205                 return rc;
 206         }
 207
 208         if (rc >= (int)(sizeof(module_regtable) / sizeof(struct module_regtable_t))
 209                 || module_regtable[rc].proc == NULL)
 210         {
 211                 Debug(LDAP_DEBUG_CONFIG, "module %s: unknown registration type (%d)\n",
 212                         file_name, rc, 0);
 213
 214                 module_int_unload(module);
 215                 return -1;
 216         }
 217
 218         rc = (module_regtable[rc].proc)(module, file_name);
 219         if (rc != 0) {
 220                 Debug(LDAP_DEBUG_CONFIG, "module %s: %s module could not be registered\n",
 221                         file_name, module_regtable[rc].type, 0);
 222
 223                 module_int_unload(module);
 224                 return rc;
 225         }
 226
 227         module->next = module_list;
 228         module_list = module;
 229
 230         Debug(LDAP_DEBUG_CONFIG, "module %s: %s module registered\n",
 231                 file_name, module_regtable[rc].type, 0);
 232
 233         return 0;
 234 }
 235
 236 int module_path(const char *path)
 237 {
 238 #ifdef HAVE_EBCDIC
 239         strcpy(ebuf, path);
 240         __atoe(ebuf);
 241         path = ebuf;
 242 #endif
 243         return lt_dlsetsearchpath( path );
 244 }
 245
 246 void *module_resolve (const void *module, const char *name)
 247 {
 248 #ifdef HAVE_EBCDIC
 249         strcpy(ebuf, name);
 250         __atoe(ebuf);
 251         name = ebuf;
 252 #endif
 253         if (module == NULL || name == NULL)
 254                 return(NULL);
 255         return(lt_dlsym(((module_loaded_t *)module)->lib, name));
 256 }
 257
 258 static int module_int_unload (module_loaded_t *module)
 259 {
 260         module_loaded_t *mod;
 261         MODULE_TERM_FN terminate;
 262
 263         if (module != NULL) {
 264                 /* remove module from tracking list */
 265                 if (module_list == module) {
 266                         module_list = module->next;
 267                 } else {
 268                         for (mod = module_list; mod; mod = mod->next) {
 269                                 if (mod->next == module) {
 270                                         mod->next = module->next;
 271                                         break;
 272                                 }
 273                         }
 274                 }
 275
 276                 /* call module's terminate routine, if present */
 277 #ifdef HAVE_EBCDIC
 278 #pragma convlit(suspend)
 279 #endif
 280                 if ((terminate = lt_dlsym(module->lib, "term_module"))) {
 281 #ifdef HAVE_EBCDIC
 282 #pragma convlit(resume)
 283 #endif
 284                         terminate();
 285                 }
 286
 287                 /* close the library and free the memory */
 288                 lt_dlclose(module->lib);
 289                 ch_free(module);
 290         }
 291         return 0;
 292 }
 293
 294 int load_null_module (const void *module, const char *file_name)
 295 {
 296         return 0;
 297 }
 298
 299 #ifdef SLAPD_EXTERNAL_EXTENSIONS
 300 int
 301 load_extop_module (
 302         const void *module,
 303         const char *file_name
 304 )
 305 {
 306         SLAP_EXTOP_MAIN_FN *ext_main;
 307         SLAP_EXTOP_GETOID_FN *ext_getoid;
 308         struct berval oid;
 309         int rc;
 310
 311         ext_main = (SLAP_EXTOP_MAIN_FN *)module_resolve(module, "ext_main");
 312         if (ext_main == NULL) {
 313                 return(-1);
 314         }
 315
 316         ext_getoid = module_resolve(module, "ext_getoid");
 317         if (ext_getoid == NULL) {
 318                 return(-1);
 319         }
 320
 321         rc = (ext_getoid)(0, &oid, 256);
 322         if (rc != 0) {
 323                 return(rc);
 324         }
 325         if (oid.bv_val == NULL || oid.bv_len == 0) {
 326                 return(-1);
 327         }
 328
 329         /* FIXME: this is broken, and no longer needed,
 330          * as a module can call load_extop() itself... */
 331         rc = load_extop( &oid, ext_main );
 332         return rc;
 333 }
 334 #endif /* SLAPD_EXTERNAL_EXTENSIONS */
 335 #endif /* SLAPD_MODULES */
 336