git.sur5r.net Git - openldap/blob - servers/slapd/backover.c

   1 /* backover.c - backend overlay routines */
   2 /* $OpenLDAP$ */
   3 /* This work is part of OpenLDAP Software <http://www.openldap.org/>.
   4  *
   5  * Copyright 2003-2016 The OpenLDAP Foundation.
   6  * All rights reserved.
   7  *
   8  * Redistribution and use in source and binary forms, with or without
   9  * modification, are permitted only as authorized by the OpenLDAP
  10  * Public License.
  11  *
  12  * A copy of this license is available in the file LICENSE in the
  13  * top-level directory of the distribution or, alternatively, at
  14  * <http://www.OpenLDAP.org/license.html>.
  15  */
  16
  17 /* Functions to overlay other modules over a backend. */
  18
  19 #include "portable.h"
  20
  21 #include <stdio.h>
  22
  23 #include <ac/string.h>
  24 #include <ac/socket.h>
  25
  26 #define SLAPD_TOOLS
  27 #include "slap.h"
  28 #include "config.h"
  29
  30 static slap_overinst *overlays;
  31
  32 static int
  33 over_db_config(
  34         BackendDB *be,
  35         const char *fname,
  36         int lineno,
  37         int argc,
  38         char **argv
  39 )
  40 {
  41         slap_overinfo *oi = be->bd_info->bi_private;
  42         slap_overinst *on = oi->oi_list;
  43         BackendInfo *bi_orig = be->bd_info;
  44         struct ConfigOCs *be_cf_ocs = be->be_cf_ocs;
  45         ConfigArgs ca = {0};
  46         int rc = 0;
  47
  48         if ( oi->oi_orig->bi_db_config ) {
  49                 be->bd_info = oi->oi_orig;
  50                 be->be_cf_ocs = oi->oi_orig->bi_cf_ocs;
  51                 rc = oi->oi_orig->bi_db_config( be, fname, lineno,
  52                         argc, argv );
  53
  54                 if ( be->bd_info != oi->oi_orig ) {
  55                         slap_overinfo   *oi2;
  56                         slap_overinst   *on2, **onp;
  57                         BackendDB       be2 = *be;
  58                         int             i;
  59
  60                         /* a database added an overlay;
  61                          * work it around... */
  62                         assert( overlay_is_over( be ) );
  63
  64                         oi2 = ( slap_overinfo * )be->bd_info->bi_private;
  65                         on2 = oi2->oi_list;
  66
  67                         /* need to put a uniqueness check here as well;
  68                          * note that in principle there could be more than
  69                          * one overlay as a result of multiple calls to
  70                          * overlay_config() */
  71                         be2.bd_info = (BackendInfo *)oi;
  72
  73                         for ( i = 0, onp = &on2; *onp; i++, onp = &(*onp)->on_next ) {
  74                                 if ( overlay_is_inst( &be2, (*onp)->on_bi.bi_type ) ) {
  75                                         Debug( LDAP_DEBUG_ANY, "over_db_config(): "
  76                                                         "warning, freshly added "
  77                                                         "overlay #%d \"%s\" is already in list\n",
  78                                                         i, (*onp)->on_bi.bi_type, 0 );
  79
  80                                         /* NOTE: if the overlay already exists,
  81                                          * there is no way to merge the results
  82                                          * of the configuration that may have
  83                                          * occurred during bi_db_config(); we
  84                                          * just issue a warning, and the
  85                                          * administrator should deal with this */
  86                                 }
  87                         }
  88                         *onp = oi->oi_list;
  89
  90                         oi->oi_list = on2;
  91
  92                         ch_free( be->bd_info );
  93                 }
  94
  95                 be->bd_info = (BackendInfo *)oi;
  96                 if ( rc != SLAP_CONF_UNKNOWN ) return rc;
  97         }
  98
  99         ca.argv = argv;
 100         ca.argc = argc;
 101         ca.fname = fname;
 102         ca.lineno = lineno;
 103         ca.be = be;
 104         snprintf( ca.log, sizeof( ca.log ), "%s: line %d",
 105                         ca.fname, ca.lineno );
 106         ca.op = SLAP_CONFIG_ADD;
 107         ca.valx = -1;
 108
 109         for (; on; on=on->on_next) {
 110                 rc = SLAP_CONF_UNKNOWN;
 111                 if (on->on_bi.bi_cf_ocs) {
 112                         ConfigTable *ct;
 113                         ca.bi = &on->on_bi;
 114                         ct = config_find_keyword( on->on_bi.bi_cf_ocs->co_table, &ca );
 115                         if ( ct ) {
 116                                 ca.table = on->on_bi.bi_cf_ocs->co_type;
 117                                 rc = config_add_vals( ct, &ca );
 118                                 if ( rc != SLAP_CONF_UNKNOWN )
 119                                         break;
 120                         }
 121                 }
 122                 if (on->on_bi.bi_db_config && rc == SLAP_CONF_UNKNOWN) {
 123                         be->bd_info = &on->on_bi;
 124                         rc = on->on_bi.bi_db_config( be, fname, lineno,
 125                                 argc, argv );
 126                         if ( rc != SLAP_CONF_UNKNOWN ) break;
 127                 }
 128         }
 129         be->bd_info = bi_orig;
 130         be->be_cf_ocs = be_cf_ocs;
 131
 132         return rc;
 133 }
 134
 135 static int
 136 over_db_open(
 137         BackendDB *be,
 138         ConfigReply *cr
 139 )
 140 {
 141         slap_overinfo *oi = be->bd_info->bi_private;
 142         slap_overinst *on = oi->oi_list;
 143         BackendDB db = *be;
 144         int rc = 0;
 145
 146         db.be_flags |= SLAP_DBFLAG_OVERLAY;
 147         db.bd_info = oi->oi_orig;
 148         if ( db.bd_info->bi_db_open ) {
 149                 rc = db.bd_info->bi_db_open( &db, cr );
 150         }
 151
 152         for (; on && rc == 0; on=on->on_next) {
 153                 if ( on->on_bi.bi_flags & SLAPO_BFLAG_DISABLED )
 154                         continue;
 155                 db.bd_info = &on->on_bi;
 156                 if ( db.bd_info->bi_db_open ) {
 157                         rc = db.bd_info->bi_db_open( &db, cr );
 158                 }
 159         }
 160
 161         return rc;
 162 }
 163
 164 static int
 165 over_db_close(
 166         BackendDB *be,
 167         ConfigReply *cr
 168 )
 169 {
 170         slap_overinfo *oi = be->bd_info->bi_private;
 171         slap_overinst *on = oi->oi_list;
 172         BackendInfo *bi_orig = be->bd_info;
 173         int rc = 0;
 174
 175         for (; on && rc == 0; on=on->on_next) {
 176                 if ( on->on_bi.bi_flags & SLAPO_BFLAG_DISABLED )
 177                         continue;
 178                 be->bd_info = &on->on_bi;
 179                 if ( be->bd_info->bi_db_close ) {
 180                         rc = be->bd_info->bi_db_close( be, cr );
 181                 }
 182         }
 183
 184         if ( oi->oi_orig->bi_db_close ) {
 185                 be->bd_info = oi->oi_orig;
 186                 rc = be->bd_info->bi_db_close( be, cr );
 187         }
 188
 189         be->bd_info = bi_orig;
 190         return rc;
 191 }
 192
 193 static int
 194 over_db_destroy(
 195         BackendDB *be,
 196         ConfigReply *cr
 197 )
 198 {
 199         slap_overinfo *oi = be->bd_info->bi_private;
 200         slap_overinst *on = oi->oi_list, *next;
 201         BackendInfo *bi_orig = be->bd_info;
 202         int rc = 0;
 203
 204         be->bd_info = oi->oi_orig;
 205         if ( be->bd_info->bi_db_destroy ) {
 206                 rc = be->bd_info->bi_db_destroy( be, cr );
 207         }
 208
 209         for (; on && rc == 0; on=on->on_next) {
 210                 if ( on->on_bi.bi_flags & SLAPO_BFLAG_DISABLED )
 211                         continue;
 212                 be->bd_info = &on->on_bi;
 213                 if ( be->bd_info->bi_db_destroy ) {
 214                         rc = be->bd_info->bi_db_destroy( be, cr );
 215                 }
 216         }
 217
 218         on = oi->oi_list;
 219         if ( on ) {
 220                 for (next = on->on_next; on; on=next) {
 221                         next = on->on_next;
 222                         free( on );
 223                 }
 224         }
 225         be->bd_info = bi_orig;
 226         free( oi );
 227         return rc;
 228 }
 229
 230 static int
 231 over_back_response ( Operation *op, SlapReply *rs )
 232 {
 233         slap_overinfo *oi = op->o_callback->sc_private;
 234         slap_overinst *on = oi->oi_list;
 235         int rc = SLAP_CB_CONTINUE;
 236         BackendDB *be = op->o_bd, db = *op->o_bd;
 237
 238         db.be_flags |= SLAP_DBFLAG_OVERLAY;
 239         op->o_bd = &db;
 240         for (; on; on=on->on_next ) {
 241                 if ( on->on_bi.bi_flags & SLAPO_BFLAG_DISABLED )
 242                         continue;
 243                 if ( on->on_response ) {
 244                         db.bd_info = (BackendInfo *)on;
 245                         rc = on->on_response( op, rs );
 246                         if ( rc != SLAP_CB_CONTINUE ) break;
 247                 }
 248         }
 249         /* Bypass the remaining on_response layers, but allow
 250          * normal execution to continue.
 251          */
 252         if ( rc == SLAP_CB_BYPASS )
 253                 rc = SLAP_CB_CONTINUE;
 254         op->o_bd = be;
 255         return rc;
 256 }
 257
 258 static int
 259 over_access_allowed(
 260         Operation               *op,
 261         Entry                   *e,
 262         AttributeDescription    *desc,
 263         struct berval           *val,
 264         slap_access_t           access,
 265         AccessControlState      *state,
 266         slap_mask_t             *maskp )
 267 {
 268         slap_overinfo *oi;
 269         slap_overinst *on;
 270         BackendInfo *bi;
 271         BackendDB *be = op->o_bd, db;
 272         int rc = SLAP_CB_CONTINUE;
 273
 274         /* FIXME: used to happen for instance during abandon
 275          * when global overlays are used... */
 276         assert( op->o_bd != NULL );
 277
 278         bi = op->o_bd->bd_info;
 279         /* Were we invoked on the frontend? */
 280         if ( !bi->bi_access_allowed ) {
 281                 oi = frontendDB->bd_info->bi_private;
 282         } else {
 283                 oi = op->o_bd->bd_info->bi_private;
 284         }
 285         on = oi->oi_list;
 286
 287         for ( ; on; on = on->on_next ) {
 288                 if ( on->on_bi.bi_flags & SLAPO_BFLAG_DISABLED )
 289                         continue;
 290                 if ( on->on_bi.bi_access_allowed ) {
 291                         /* NOTE: do not copy the structure until required */
 292                         if ( !SLAP_ISOVERLAY( op->o_bd ) ) {
 293                                 db = *op->o_bd;
 294                                 db.be_flags |= SLAP_DBFLAG_OVERLAY;
 295                                 op->o_bd = &db;
 296                         }
 297
 298                         op->o_bd->bd_info = (BackendInfo *)on;
 299                         rc = on->on_bi.bi_access_allowed( op, e,
 300                                 desc, val, access, state, maskp );
 301                         if ( rc != SLAP_CB_CONTINUE ) break;
 302                 }
 303         }
 304
 305         if ( rc == SLAP_CB_CONTINUE ) {
 306                 BI_access_allowed       *bi_access_allowed;
 307
 308                 /* if the database structure was changed, o_bd points to a
 309                  * copy of the structure; put the original bd_info in place */
 310                 if ( SLAP_ISOVERLAY( op->o_bd ) ) {
 311                         op->o_bd->bd_info = oi->oi_orig;
 312                 }
 313
 314                 if ( oi->oi_orig->bi_access_allowed ) {
 315                         bi_access_allowed = oi->oi_orig->bi_access_allowed;
 316                 } else {
 317                         bi_access_allowed = slap_access_allowed;
 318                 }
 319
 320                 rc = bi_access_allowed( op, e,
 321                         desc, val, access, state, maskp );
 322         }
 323         /* should not fall thru this far without anything happening... */
 324         if ( rc == SLAP_CB_CONTINUE ) {
 325                 /* access not allowed */
 326                 rc = 0;
 327         }
 328
 329         op->o_bd = be;
 330         op->o_bd->bd_info = bi;
 331
 332         return rc;
 333 }
 334
 335 int
 336 overlay_entry_get_ov(
 337         Operation               *op,
 338         struct berval   *dn,
 339         ObjectClass             *oc,
 340         AttributeDescription    *ad,
 341         int     rw,
 342         Entry   **e,
 343         slap_overinst *on )
 344 {
 345         slap_overinfo *oi = on->on_info;
 346         BackendDB *be = op->o_bd, db;
 347         BackendInfo *bi = op->o_bd->bd_info;
 348         int rc = SLAP_CB_CONTINUE;
 349
 350         for ( ; on; on = on->on_next ) {
 351                 if ( on->on_bi.bi_flags & SLAPO_BFLAG_DISABLED )
 352                         continue;
 353                 if ( on->on_bi.bi_entry_get_rw ) {
 354                         /* NOTE: do not copy the structure until required */
 355                         if ( !SLAP_ISOVERLAY( op->o_bd ) ) {
 356                                 db = *op->o_bd;
 357                                 db.be_flags |= SLAP_DBFLAG_OVERLAY;
 358                                 op->o_bd = &db;
 359                         }
 360
 361                         op->o_bd->bd_info = (BackendInfo *)on;
 362                         rc = on->on_bi.bi_entry_get_rw( op, dn,
 363                                 oc, ad, rw, e );
 364                         if ( rc != SLAP_CB_CONTINUE ) break;
 365                 }
 366         }
 367
 368         if ( rc == SLAP_CB_CONTINUE ) {
 369                 /* if the database structure was changed, o_bd points to a
 370                  * copy of the structure; put the original bd_info in place */
 371                 if ( SLAP_ISOVERLAY( op->o_bd ) ) {
 372                         op->o_bd->bd_info = oi->oi_orig;
 373                 }
 374
 375                 if ( oi->oi_orig->bi_entry_get_rw ) {
 376                         rc = oi->oi_orig->bi_entry_get_rw( op, dn,
 377                                 oc, ad, rw, e );
 378                 }
 379         }
 380         /* should not fall thru this far without anything happening... */
 381         if ( rc == SLAP_CB_CONTINUE ) {
 382                 rc = LDAP_UNWILLING_TO_PERFORM;
 383         }
 384
 385         op->o_bd = be;
 386         op->o_bd->bd_info = bi;
 387
 388         return rc;
 389 }
 390
 391 static int
 392 over_entry_get_rw(
 393         Operation               *op,
 394         struct berval   *dn,
 395         ObjectClass             *oc,
 396         AttributeDescription    *ad,
 397         int     rw,
 398         Entry   **e )
 399 {
 400         slap_overinfo *oi;
 401         slap_overinst *on;
 402
 403         assert( op->o_bd != NULL );
 404
 405         oi = op->o_bd->bd_info->bi_private;
 406         on = oi->oi_list;
 407
 408         return overlay_entry_get_ov( op, dn, oc, ad, rw, e, on );
 409 }
 410
 411 int
 412 overlay_entry_release_ov(
 413         Operation       *op,
 414         Entry   *e,
 415         int rw,
 416         slap_overinst *on )
 417 {
 418         slap_overinfo *oi = on->on_info;
 419         BackendDB *be = op->o_bd, db;
 420         BackendInfo *bi = op->o_bd->bd_info;
 421         int rc = SLAP_CB_CONTINUE;
 422
 423         for ( ; on; on = on->on_next ) {
 424                 if ( on->on_bi.bi_flags & SLAPO_BFLAG_DISABLED )
 425                         continue;
 426                 if ( on->on_bi.bi_entry_release_rw ) {
 427                         /* NOTE: do not copy the structure until required */
 428                         if ( !SLAP_ISOVERLAY( op->o_bd ) ) {
 429                                 db = *op->o_bd;
 430                                 db.be_flags |= SLAP_DBFLAG_OVERLAY;
 431                                 op->o_bd = &db;
 432                         }
 433
 434                         op->o_bd->bd_info = (BackendInfo *)on;
 435                         rc = on->on_bi.bi_entry_release_rw( op, e, rw );
 436                         if ( rc != SLAP_CB_CONTINUE ) break;
 437                 }
 438         }
 439
 440         if ( rc == SLAP_CB_CONTINUE ) {
 441                 /* if the database structure was changed, o_bd points to a
 442                  * copy of the structure; put the original bd_info in place */
 443                 if ( SLAP_ISOVERLAY( op->o_bd ) ) {
 444                         op->o_bd->bd_info = oi->oi_orig;
 445                 }
 446
 447                 if ( oi->oi_orig->bi_entry_release_rw ) {
 448                         rc = oi->oi_orig->bi_entry_release_rw( op, e, rw );
 449                 }
 450         }
 451         /* should not fall thru this far without anything happening... */
 452         if ( rc == SLAP_CB_CONTINUE ) {
 453                 entry_free( e );
 454                 rc = 0;
 455         }
 456
 457         op->o_bd = be;
 458         op->o_bd->bd_info = bi;
 459
 460         return rc;
 461 }
 462
 463 static int
 464 over_entry_release_rw(
 465         Operation       *op,
 466         Entry   *e,
 467         int rw )
 468 {
 469         slap_overinfo *oi;
 470         slap_overinst *on;
 471
 472         assert( op->o_bd != NULL );
 473
 474         oi = op->o_bd->bd_info->bi_private;
 475         on = oi->oi_list;
 476
 477         return overlay_entry_release_ov( op, e, rw, on );
 478 }
 479
 480 static int
 481 over_acl_group(
 482         Operation               *op,
 483         Entry                   *e,
 484         struct berval           *gr_ndn,
 485         struct berval           *op_ndn,
 486         ObjectClass             *group_oc,
 487         AttributeDescription    *group_at )
 488 {
 489         slap_overinfo *oi;
 490         slap_overinst *on;
 491         BackendInfo *bi;
 492         BackendDB *be = op->o_bd, db;
 493         int rc = SLAP_CB_CONTINUE;
 494
 495         /* FIXME: used to happen for instance during abandon
 496          * when global overlays are used... */
 497         assert( be != NULL );
 498
 499         bi = be->bd_info;
 500         oi = bi->bi_private;
 501         on = oi->oi_list;
 502
 503         for ( ; on; on = on->on_next ) {
 504                 if ( on->on_bi.bi_flags & SLAPO_BFLAG_DISABLED )
 505                         continue;
 506                 if ( on->on_bi.bi_acl_group ) {
 507                         /* NOTE: do not copy the structure until required */
 508                         if ( !SLAP_ISOVERLAY( op->o_bd ) ) {
 509                                 db = *op->o_bd;
 510                                 db.be_flags |= SLAP_DBFLAG_OVERLAY;
 511                                 op->o_bd = &db;
 512                         }
 513
 514                         op->o_bd->bd_info = (BackendInfo *)on;
 515                         rc = on->on_bi.bi_acl_group( op, e,
 516                                 gr_ndn, op_ndn, group_oc, group_at );
 517                         if ( rc != SLAP_CB_CONTINUE ) break;
 518                 }
 519         }
 520
 521         if ( rc == SLAP_CB_CONTINUE ) {
 522                 BI_acl_group            *bi_acl_group;
 523
 524                 /* if the database structure was changed, o_bd points to a
 525                  * copy of the structure; put the original bd_info in place */
 526                 if ( SLAP_ISOVERLAY( op->o_bd ) ) {
 527                         op->o_bd->bd_info = oi->oi_orig;
 528                 }
 529
 530                 if ( oi->oi_orig->bi_acl_group ) {
 531                         bi_acl_group = oi->oi_orig->bi_acl_group;
 532                 } else {
 533                         bi_acl_group = backend_group;
 534                 }
 535
 536                 rc = bi_acl_group( op, e,
 537                         gr_ndn, op_ndn, group_oc, group_at );
 538         }
 539         /* should not fall thru this far without anything happening... */
 540         if ( rc == SLAP_CB_CONTINUE ) {
 541                 /* access not allowed */
 542                 rc = 0;
 543         }
 544
 545         op->o_bd = be;
 546         op->o_bd->bd_info = bi;
 547
 548         return rc;
 549 }
 550
 551 static int
 552 over_acl_attribute(
 553         Operation               *op,
 554         Entry                   *target,
 555         struct berval           *entry_ndn,
 556         AttributeDescription    *entry_at,
 557         BerVarray               *vals,
 558         slap_access_t           access )
 559 {
 560         slap_overinfo *oi;
 561         slap_overinst *on;
 562         BackendInfo *bi;
 563         BackendDB *be = op->o_bd, db;
 564         int rc = SLAP_CB_CONTINUE;
 565
 566         /* FIXME: used to happen for instance during abandon
 567          * when global overlays are used... */
 568         assert( be != NULL );
 569
 570         bi = be->bd_info;
 571         oi = bi->bi_private;
 572         on = oi->oi_list;
 573
 574         for ( ; on; on = on->on_next ) {
 575                 if ( on->on_bi.bi_flags & SLAPO_BFLAG_DISABLED )
 576                         continue;
 577                 if ( on->on_bi.bi_acl_attribute ) {
 578                         /* NOTE: do not copy the structure until required */
 579                         if ( !SLAP_ISOVERLAY( op->o_bd ) ) {
 580                                 db = *op->o_bd;
 581                                 db.be_flags |= SLAP_DBFLAG_OVERLAY;
 582                                 op->o_bd = &db;
 583                         }
 584
 585                         op->o_bd->bd_info = (BackendInfo *)on;
 586                         rc = on->on_bi.bi_acl_attribute( op, target,
 587                                 entry_ndn, entry_at, vals, access );
 588                         if ( rc != SLAP_CB_CONTINUE ) break;
 589                 }
 590         }
 591
 592         if ( rc == SLAP_CB_CONTINUE ) {
 593                 BI_acl_attribute                *bi_acl_attribute;
 594
 595                 /* if the database structure was changed, o_bd points to a
 596                  * copy of the structure; put the original bd_info in place */
 597                 if ( SLAP_ISOVERLAY( op->o_bd ) ) {
 598                         op->o_bd->bd_info = oi->oi_orig;
 599                 }
 600
 601                 if ( oi->oi_orig->bi_acl_attribute ) {
 602                         bi_acl_attribute = oi->oi_orig->bi_acl_attribute;
 603                 } else {
 604                         bi_acl_attribute = backend_attribute;
 605                 }
 606
 607                 rc = bi_acl_attribute( op, target,
 608                         entry_ndn, entry_at, vals, access );
 609         }
 610         /* should not fall thru this far without anything happening... */
 611         if ( rc == SLAP_CB_CONTINUE ) {
 612                 /* access not allowed */
 613                 rc = 0;
 614         }
 615
 616         op->o_bd = be;
 617         op->o_bd->bd_info = bi;
 618
 619         return rc;
 620 }
 621
 622 int
 623 overlay_callback_after_backover( Operation *op, slap_callback *sc, int append )
 624 {
 625         slap_callback **scp;
 626
 627         for ( scp = &op->o_callback; *scp != NULL; scp = &(*scp)->sc_next ) {
 628                 if ( (*scp)->sc_response == over_back_response ) {
 629                         sc->sc_next = (*scp)->sc_next;
 630                         (*scp)->sc_next = sc;
 631                         return 0;
 632                 }
 633         }
 634
 635         if ( append ) {
 636                 *scp = sc;
 637                 return 0;
 638         }
 639
 640         return 1;
 641 }
 642
 643 /*
 644  * default return code in case of missing backend function
 645  * and overlay stack returning SLAP_CB_CONTINUE
 646  */
 647 static int op_rc[ op_last ] = {
 648         LDAP_UNWILLING_TO_PERFORM,      /* bind */
 649         LDAP_UNWILLING_TO_PERFORM,      /* unbind */
 650         LDAP_UNWILLING_TO_PERFORM,      /* search */
 651         SLAP_CB_CONTINUE,               /* compare; pass to frontend */
 652         LDAP_UNWILLING_TO_PERFORM,      /* modify */
 653         LDAP_UNWILLING_TO_PERFORM,      /* modrdn */
 654         LDAP_UNWILLING_TO_PERFORM,      /* add */
 655         LDAP_UNWILLING_TO_PERFORM,      /* delete */
 656         LDAP_UNWILLING_TO_PERFORM,      /* abandon */
 657         LDAP_UNWILLING_TO_PERFORM,      /* cancel */
 658         LDAP_UNWILLING_TO_PERFORM,      /* extended */
 659         LDAP_SUCCESS,                   /* aux_operational */
 660         LDAP_SUCCESS,                   /* aux_chk_referrals */
 661         SLAP_CB_CONTINUE                /* aux_chk_controls; pass to frontend */
 662 };
 663
 664 int overlay_op_walk(
 665         Operation *op,
 666         SlapReply *rs,
 667         slap_operation_t which,
 668         slap_overinfo *oi,
 669         slap_overinst *on
 670 )
 671 {
 672         BackendInfo *bi;
 673         int rc = SLAP_CB_CONTINUE;
 674
 675         for (; on; on=on->on_next ) {
 676                 if ( on->on_bi.bi_flags & SLAPO_BFLAG_DISABLED )
 677                         continue;
 678                 bi = &on->on_bi;
 679                 if ( (&bi->bi_op_bind)[ which ] ) {
 680                         op->o_bd->bd_info = (BackendInfo *)on;
 681                         rc = (&bi->bi_op_bind)[ which ]( op, rs );
 682                         if ( rc != SLAP_CB_CONTINUE ) break;
 683                 }
 684         }
 685         if ( rc == SLAP_CB_BYPASS )
 686                 rc = SLAP_CB_CONTINUE;
 687         /* if an overlay halted processing, make sure
 688          * any previously set cleanup handlers are run
 689          */
 690         if ( rc != SLAP_CB_CONTINUE )
 691                 goto cleanup;
 692
 693         bi = oi->oi_orig;
 694         if ( (&bi->bi_op_bind)[ which ] ) {
 695                 op->o_bd->bd_info = bi;
 696                 rc = (&bi->bi_op_bind)[ which ]( op, rs );
 697         }
 698         /* should not fall thru this far without anything happening... */
 699         if ( rc == SLAP_CB_CONTINUE ) {
 700                 rc = op_rc[ which ];
 701         }
 702
 703         /* The underlying backend didn't handle the request, make sure
 704          * overlay cleanup is processed.
 705          */
 706         if ( rc == LDAP_UNWILLING_TO_PERFORM ) {
 707                 slap_callback *sc_next;
 708 cleanup:
 709                 for ( ; op->o_callback && op->o_callback->sc_response !=
 710                         over_back_response; op->o_callback = sc_next ) {
 711                         sc_next = op->o_callback->sc_next;
 712                         if ( op->o_callback->sc_cleanup ) {
 713                                 op->o_callback->sc_cleanup( op, rs );
 714                         }
 715                 }
 716         }
 717         return rc;
 718 }
 719
 720 static int
 721 over_op_func(
 722         Operation *op,
 723         SlapReply *rs,
 724         slap_operation_t which
 725 )
 726 {
 727         slap_overinfo *oi;
 728         slap_overinst *on;
 729         BackendDB *be = op->o_bd, db;
 730         slap_callback **sc;
 731         slap_callback *cb = (slap_callback *) ch_malloc( sizeof( slap_callback ));
 732         int rc = SLAP_CB_CONTINUE;
 733
 734         /* FIXME: used to happen for instance during abandon
 735          * when global overlays are used... */
 736         assert( op->o_bd != NULL );
 737
 738         oi = op->o_bd->bd_info->bi_private;
 739         on = oi->oi_list;
 740
 741         if ( !SLAP_ISOVERLAY( op->o_bd )) {
 742                 db = *op->o_bd;
 743                 db.be_flags |= SLAP_DBFLAG_OVERLAY;
 744                 op->o_bd = &db;
 745         }
 746         cb->sc_cleanup = NULL;
 747         cb->sc_response = over_back_response;
 748         cb->sc_writewait = NULL;
 749         cb->sc_next = op->o_callback;
 750         cb->sc_private = oi;
 751         op->o_callback = cb;
 752
 753         rc = overlay_op_walk( op, rs, which, oi, on );
 754         for ( sc = &op->o_callback; *sc; sc = &(*sc)->sc_next ) {
 755                 if ( *sc == cb ) {
 756                         *sc = cb->sc_next;
 757                         ch_free( cb );
 758                         break;
 759                 }
 760         }
 761
 762         op->o_bd = be;
 763         return rc;
 764 }
 765
 766 static int
 767 over_op_bind( Operation *op, SlapReply *rs )
 768 {
 769         return over_op_func( op, rs, op_bind );
 770 }
 771
 772 static int
 773 over_op_unbind( Operation *op, SlapReply *rs )
 774 {
 775         return over_op_func( op, rs, op_unbind );
 776 }
 777
 778 static int
 779 over_op_search( Operation *op, SlapReply *rs )
 780 {
 781         return over_op_func( op, rs, op_search );
 782 }
 783
 784 static int
 785 over_op_compare( Operation *op, SlapReply *rs )
 786 {
 787         return over_op_func( op, rs, op_compare );
 788 }
 789
 790 static int
 791 over_op_modify( Operation *op, SlapReply *rs )
 792 {
 793         return over_op_func( op, rs, op_modify );
 794 }
 795
 796 static int
 797 over_op_modrdn( Operation *op, SlapReply *rs )
 798 {
 799         return over_op_func( op, rs, op_modrdn );
 800 }
 801
 802 static int
 803 over_op_add( Operation *op, SlapReply *rs )
 804 {
 805         return over_op_func( op, rs, op_add );
 806 }
 807
 808 static int
 809 over_op_delete( Operation *op, SlapReply *rs )
 810 {
 811         return over_op_func( op, rs, op_delete );
 812 }
 813
 814 static int
 815 over_op_abandon( Operation *op, SlapReply *rs )
 816 {
 817         return over_op_func( op, rs, op_abandon );
 818 }
 819
 820 static int
 821 over_op_cancel( Operation *op, SlapReply *rs )
 822 {
 823         return over_op_func( op, rs, op_cancel );
 824 }
 825
 826 static int
 827 over_op_extended( Operation *op, SlapReply *rs )
 828 {
 829         return over_op_func( op, rs, op_extended );
 830 }
 831
 832 static int
 833 over_aux_operational( Operation *op, SlapReply *rs )
 834 {
 835         return over_op_func( op, rs, op_aux_operational );
 836 }
 837
 838 static int
 839 over_aux_chk_referrals( Operation *op, SlapReply *rs )
 840 {
 841         return over_op_func( op, rs, op_aux_chk_referrals );
 842 }
 843
 844 static int
 845 over_aux_chk_controls( Operation *op, SlapReply *rs )
 846 {
 847         return over_op_func( op, rs, op_aux_chk_controls );
 848 }
 849
 850 enum conn_which {
 851         conn_init = 0,
 852         conn_destroy,
 853         conn_last
 854 };
 855
 856 static int
 857 over_connection_func(
 858         BackendDB       *bd,
 859         Connection      *conn,
 860         enum conn_which which
 861 )
 862 {
 863         slap_overinfo           *oi;
 864         slap_overinst           *on;
 865         BackendDB               db;
 866         int                     rc = SLAP_CB_CONTINUE;
 867         BI_connection_init      **func;
 868
 869         /* FIXME: used to happen for instance during abandon
 870          * when global overlays are used... */
 871         assert( bd != NULL );
 872
 873         oi = bd->bd_info->bi_private;
 874         on = oi->oi_list;
 875
 876         if ( !SLAP_ISOVERLAY( bd ) ) {
 877                 db = *bd;
 878                 db.be_flags |= SLAP_DBFLAG_OVERLAY;
 879                 bd = &db;
 880         }
 881
 882         for ( ; on; on = on->on_next ) {
 883                 if ( on->on_bi.bi_flags & SLAPO_BFLAG_DISABLED )
 884                         continue;
 885                 func = &on->on_bi.bi_connection_init;
 886                 if ( func[ which ] ) {
 887                         bd->bd_info = (BackendInfo *)on;
 888                         rc = func[ which ]( bd, conn );
 889                         if ( rc != SLAP_CB_CONTINUE ) break;
 890                 }
 891         }
 892
 893         func = &oi->oi_orig->bi_connection_init;
 894         if ( func[ which ] && rc == SLAP_CB_CONTINUE ) {
 895                 bd->bd_info = oi->oi_orig;
 896                 rc = func[ which ]( bd, conn );
 897         }
 898         /* should not fall thru this far without anything happening... */
 899         if ( rc == SLAP_CB_CONTINUE ) {
 900                 rc = LDAP_UNWILLING_TO_PERFORM;
 901         }
 902
 903         return rc;
 904 }
 905
 906 static int
 907 over_connection_init(
 908         BackendDB       *bd,
 909         Connection      *conn
 910 )
 911 {
 912         return over_connection_func( bd, conn, conn_init );
 913 }
 914
 915 static int
 916 over_connection_destroy(
 917         BackendDB       *bd,
 918         Connection      *conn
 919 )
 920 {
 921         return over_connection_func( bd, conn, conn_destroy );
 922 }
 923
 924 int
 925 overlay_register(
 926         slap_overinst *on
 927 )
 928 {
 929         slap_overinst   *tmp;
 930
 931         /* FIXME: check for duplicates? */
 932         for ( tmp = overlays; tmp != NULL; tmp = tmp->on_next ) {
 933                 if ( strcmp( on->on_bi.bi_type, tmp->on_bi.bi_type ) == 0 ) {
 934                         Debug( LDAP_DEBUG_ANY,
 935                                 "overlay_register(\"%s\"): "
 936                                 "name already in use.\n",
 937                                 on->on_bi.bi_type, 0, 0 );
 938                         return -1;
 939                 }
 940
 941                 if ( on->on_bi.bi_obsolete_names != NULL ) {
 942                         int     i;
 943
 944                         for ( i = 0; on->on_bi.bi_obsolete_names[ i ] != NULL; i++ ) {
 945                                 if ( strcmp( on->on_bi.bi_obsolete_names[ i ], tmp->on_bi.bi_type ) == 0 ) {
 946                                         Debug( LDAP_DEBUG_ANY,
 947                                                 "overlay_register(\"%s\"): "
 948                                                 "obsolete name \"%s\" already in use "
 949                                                 "by overlay \"%s\".\n",
 950                                                 on->on_bi.bi_type,
 951                                                 on->on_bi.bi_obsolete_names[ i ],
 952                                                 tmp->on_bi.bi_type );
 953                                         return -1;
 954                                 }
 955                         }
 956                 }
 957
 958                 if ( tmp->on_bi.bi_obsolete_names != NULL ) {
 959                         int     i;
 960
 961                         for ( i = 0; tmp->on_bi.bi_obsolete_names[ i ] != NULL; i++ ) {
 962                                 int     j;
 963
 964                                 if ( strcmp( on->on_bi.bi_type, tmp->on_bi.bi_obsolete_names[ i ] ) == 0 ) {
 965                                         Debug( LDAP_DEBUG_ANY,
 966                                                 "overlay_register(\"%s\"): "
 967                                                 "name already in use "
 968                                                 "as obsolete by overlay \"%s\".\n",
 969                                                 on->on_bi.bi_type,
 970                                                 tmp->on_bi.bi_obsolete_names[ i ], 0 );
 971                                         return -1;
 972                                 }
 973
 974                                 if ( on->on_bi.bi_obsolete_names != NULL ) {
 975                                         for ( j = 0; on->on_bi.bi_obsolete_names[ j ] != NULL; j++ ) {
 976                                                 if ( strcmp( on->on_bi.bi_obsolete_names[ j ], tmp->on_bi.bi_obsolete_names[ i ] ) == 0 ) {
 977                                                         Debug( LDAP_DEBUG_ANY,
 978                                                                 "overlay_register(\"%s\"): "
 979                                                                 "obsolete name \"%s\" already in use "
 980                                                                 "as obsolete by overlay \"%s\".\n",
 981                                                                 on->on_bi.bi_type,
 982                                                                 on->on_bi.bi_obsolete_names[ j ],
 983                                                                 tmp->on_bi.bi_type );
 984                                                         return -1;
 985                                                 }
 986                                         }
 987                                 }
 988                         }
 989                 }
 990         }
 991
 992         on->on_next = overlays;
 993         overlays = on;
 994         return 0;
 995 }
 996
 997 /*
 998  * iterator on registered overlays; overlay_next( NULL ) returns the first
 999  * overlay; subsequent calls with the previously returned value allow to
1000  * iterate over the entire list; returns NULL when no more overlays are
1001  * registered.
1002  */
1003
1004 slap_overinst *
1005 overlay_next(
1006         slap_overinst *on
1007 )
1008 {
1009         if ( on == NULL ) {
1010                 return overlays;
1011         }
1012
1013         return on->on_next;
1014 }
1015
1016 /*
1017  * returns a specific registered overlay based on the type; NULL if not
1018  * registered.
1019  */
1020
1021 slap_overinst *
1022 overlay_find( const char *over_type )
1023 {
1024         slap_overinst *on = overlays;
1025
1026         assert( over_type != NULL );
1027
1028         for ( ; on; on = on->on_next ) {
1029                 if ( strcmp( on->on_bi.bi_type, over_type ) == 0 ) {
1030                         goto foundit;
1031                 }
1032
1033                 if ( on->on_bi.bi_obsolete_names != NULL ) {
1034                         int     i;
1035
1036                         for ( i = 0; on->on_bi.bi_obsolete_names[ i ] != NULL; i++ ) {
1037                                 if ( strcmp( on->on_bi.bi_obsolete_names[ i ], over_type ) == 0 ) {
1038                                         Debug( LDAP_DEBUG_ANY,
1039                                                 "overlay_find(\"%s\"): "
1040                                                 "obsolete name for \"%s\".\n",
1041                                                 on->on_bi.bi_obsolete_names[ i ],
1042                                                 on->on_bi.bi_type, 0 );
1043                                         goto foundit;
1044                                 }
1045                         }
1046                 }
1047         }
1048
1049 foundit:;
1050         return on;
1051 }
1052
1053 static const char overtype[] = "over";
1054
1055 /*
1056  * returns TRUE (1) if the database is actually an overlay instance;
1057  * FALSE (0) otherwise.
1058  */
1059
1060 int
1061 overlay_is_over( BackendDB *be )
1062 {
1063         return be->bd_info->bi_type == overtype;
1064 }
1065
1066 /*
1067  * returns TRUE (1) if the given database is actually an overlay
1068  * instance and, somewhere in the list, contains the requested overlay;
1069  * FALSE (0) otherwise.
1070  */
1071
1072 int
1073 overlay_is_inst( BackendDB *be, const char *over_type )
1074 {
1075         slap_overinst   *on;
1076
1077         assert( be != NULL );
1078
1079         if ( !overlay_is_over( be ) ) {
1080                 return 0;
1081         }
1082
1083         on = ((slap_overinfo *)be->bd_info->bi_private)->oi_list;
1084         for ( ; on; on = on->on_next ) {
1085                 if ( strcmp( on->on_bi.bi_type, over_type ) == 0 ) {
1086                         return 1;
1087                 }
1088         }
1089
1090         return 0;
1091 }
1092
1093 int
1094 overlay_register_control( BackendDB *be, const char *oid )
1095 {
1096         int             gotit = 0;
1097         int             cid;
1098
1099         if ( slap_find_control_id( oid, &cid ) == LDAP_CONTROL_NOT_FOUND ) {
1100                 return -1;
1101         }
1102
1103         if ( SLAP_ISGLOBALOVERLAY( be ) ) {
1104                 BackendDB *bd;
1105
1106                 /* add to all backends... */
1107                 LDAP_STAILQ_FOREACH( bd, &backendDB, be_next ) {
1108                         if ( bd == be->bd_self ) {
1109                                 gotit = 1;
1110                         }
1111
1112                         /* overlays can be instanciated multiple times, use
1113                          * be_ctrls[ cid ] as an instance counter, so that the
1114                          * overlay's controls are only really disabled after the
1115                          * last instance called overlay_register_control() */
1116                         bd->be_ctrls[ cid ]++;
1117                         bd->be_ctrls[ SLAP_MAX_CIDS ] = 1;
1118                 }
1119
1120         }
1121
1122         if ( !gotit ) {
1123                 /* overlays can be instanciated multiple times, use
1124                  * be_ctrls[ cid ] as an instance counter, so that the
1125                  * overlay's controls are only really unregistered after the
1126                  * last instance called overlay_register_control() */
1127                 be->bd_self->be_ctrls[ cid ]++;
1128                 be->bd_self->be_ctrls[ SLAP_MAX_CIDS ] = 1;
1129         }
1130
1131         return 0;
1132 }
1133
1134 #ifdef SLAP_CONFIG_DELETE
1135 void
1136 overlay_unregister_control( BackendDB *be, const char *oid )
1137 {
1138         int             gotit = 0;
1139         int             cid;
1140
1141         if ( slap_find_control_id( oid, &cid ) == LDAP_CONTROL_NOT_FOUND ) {
1142                 return;
1143         }
1144
1145         if ( SLAP_ISGLOBALOVERLAY( be ) ) {
1146                 BackendDB *bd;
1147
1148                 /* remove from all backends... */
1149                 LDAP_STAILQ_FOREACH( bd, &backendDB, be_next ) {
1150                         if ( bd == be->bd_self ) {
1151                                 gotit = 1;
1152                         }
1153
1154                         bd->be_ctrls[ cid ]--;
1155                 }
1156         }
1157
1158         if ( !gotit ) {
1159                 be->bd_self->be_ctrls[ cid ]--;
1160         }
1161 }
1162 #endif /* SLAP_CONFIG_DELETE */
1163
1164 void
1165 overlay_destroy_one( BackendDB *be, slap_overinst *on )
1166 {
1167         slap_overinfo *oi = on->on_info;
1168         slap_overinst **oidx;
1169
1170         for ( oidx = &oi->oi_list; *oidx; oidx = &(*oidx)->on_next ) {
1171                 if ( *oidx == on ) {
1172                         *oidx = on->on_next;
1173                         if ( on->on_bi.bi_db_destroy ) {
1174                                 BackendInfo *bi_orig = be->bd_info;
1175                                 be->bd_info = (BackendInfo *)on;
1176                                 on->on_bi.bi_db_destroy( be, NULL );
1177                                 be->bd_info = bi_orig;
1178                         }
1179                         free( on );
1180                         break;
1181                 }
1182         }
1183 }
1184
1185 #ifdef SLAP_CONFIG_DELETE
1186 typedef struct ov_remove_ctx {
1187         BackendDB *be;
1188         slap_overinst *on;
1189 } ov_remove_ctx;
1190
1191 int
1192 overlay_remove_cb( Operation *op, SlapReply *rs )
1193 {
1194         ov_remove_ctx *rm_ctx = (ov_remove_ctx*) op->o_callback->sc_private;
1195         BackendInfo *bi_orig = rm_ctx->be->bd_info;
1196
1197         rm_ctx->be->bd_info = (BackendInfo*) rm_ctx->on;
1198
1199         if ( rm_ctx->on->on_bi.bi_db_close ) {
1200                 rm_ctx->on->on_bi.bi_db_close( rm_ctx->be, NULL );
1201         }
1202         if ( rm_ctx->on->on_bi.bi_db_destroy ) {
1203                 rm_ctx->on->on_bi.bi_db_destroy( rm_ctx->be, NULL );
1204         }
1205
1206         /* clean up after removing last overlay */
1207         if ( ! rm_ctx->on->on_info->oi_list ) {
1208                 /* reset db flags and bd_info to orig */
1209                 SLAP_DBFLAGS( rm_ctx->be ) &= ~SLAP_DBFLAG_GLOBAL_OVERLAY;
1210                 rm_ctx->be->bd_info = rm_ctx->on->on_info->oi_orig;
1211                 ch_free(rm_ctx->on->on_info);
1212         } else {
1213                 rm_ctx->be->bd_info = bi_orig;
1214         }
1215         free( rm_ctx->on );
1216         op->o_tmpfree(rm_ctx, op->o_tmpmemctx);
1217         return SLAP_CB_CONTINUE;
1218 }
1219
1220 void
1221 overlay_remove( BackendDB *be, slap_overinst *on, Operation *op )
1222 {
1223         slap_overinfo *oi = on->on_info;
1224         slap_overinst **oidx;
1225         ov_remove_ctx *rm_ctx;
1226         slap_callback *rm_cb, *cb;
1227
1228         /* remove overlay from oi_list */
1229         for ( oidx = &oi->oi_list; *oidx; oidx = &(*oidx)->on_next ) {
1230                 if ( *oidx == on ) {
1231                         *oidx = on->on_next;
1232                         break;
1233                 }
1234         }
1235
1236         /* The db_close and db_destroy handlers to cleanup a release
1237          * the overlay's resources are called from the cleanup callback
1238          */
1239         rm_ctx = op->o_tmpalloc( sizeof( ov_remove_ctx ), op->o_tmpmemctx );
1240         rm_ctx->be = be;
1241         rm_ctx->on = on;
1242
1243         rm_cb = op->o_tmpalloc( sizeof( slap_callback ), op->o_tmpmemctx );
1244         rm_cb->sc_next = NULL;
1245         rm_cb->sc_cleanup = overlay_remove_cb;
1246         rm_cb->sc_response = NULL;
1247         rm_cb->sc_private = (void*) rm_ctx;
1248
1249         /* Append callback to the end of the list */
1250         if ( !op->o_callback ) {
1251                 op->o_callback = rm_cb;
1252         } else {
1253                 for ( cb = op->o_callback; cb->sc_next; cb = cb->sc_next );
1254                 cb->sc_next = rm_cb;
1255         }
1256 }
1257 #endif /* SLAP_CONFIG_DELETE */
1258
1259 void
1260 overlay_insert( BackendDB *be, slap_overinst *on2, slap_overinst ***prev,
1261         int idx )
1262 {
1263         slap_overinfo *oi = (slap_overinfo *)be->bd_info;
1264
1265         if ( idx == -1 ) {
1266                 on2->on_next = oi->oi_list;
1267                 oi->oi_list = on2;
1268         } else {
1269                 int i, novs;
1270                 slap_overinst *on, **prev;
1271
1272                 /* Since the list is in reverse order and is singly linked,
1273                  * we have to count the overlays and then insert backwards.
1274                  * Adding on overlay at a specific point should be a pretty
1275                  * infrequent occurrence.
1276                  */
1277                 novs = 0;
1278                 for ( on = oi->oi_list; on; on=on->on_next )
1279                         novs++;
1280
1281                 if (idx > novs)
1282                         idx = 0;
1283                 else
1284                         idx = novs - idx;
1285
1286                 /* advance to insertion point */
1287                 prev = &oi->oi_list;
1288                 for ( i=0; i<idx; i++ ) {
1289                         on = *prev;
1290                         prev = &on->on_next;
1291                 }
1292                 /* insert */
1293                 on2->on_next = *prev;
1294                 *prev = on2;
1295         }
1296 }
1297
1298 void
1299 overlay_move( BackendDB *be, slap_overinst *on, int idx )
1300 {
1301         slap_overinfo *oi = (slap_overinfo *)be->bd_info;
1302         slap_overinst **onp;
1303
1304         for (onp = &oi->oi_list; *onp; onp= &(*onp)->on_next) {
1305                 if ( *onp == on ) {
1306                         *onp = on->on_next;
1307                         break;
1308                 }
1309         }
1310         overlay_insert( be, on, &onp, idx );
1311 }
1312
1313 /* add an overlay to a particular backend. */
1314 int
1315 overlay_config( BackendDB *be, const char *ov, int idx, BackendInfo **res, ConfigReply *cr )
1316 {
1317         slap_overinst *on = NULL, *on2 = NULL, **prev;
1318         slap_overinfo *oi = NULL;
1319         BackendInfo *bi = NULL;
1320
1321         if ( res )
1322                 *res = NULL;
1323
1324         on = overlay_find( ov );
1325         if ( !on ) {
1326                 Debug( LDAP_DEBUG_ANY, "overlay \"%s\" not found\n", ov, 0, 0 );
1327                 return 1;
1328         }
1329
1330         /* If this is the first overlay on this backend, set up the
1331          * overlay info structure
1332          */
1333         if ( !overlay_is_over( be ) ) {
1334                 int     isglobal = 0;
1335
1336                 /* NOTE: the first time a global overlay is configured,
1337                  * frontendDB gets this flag; it is used later by overlays
1338                  * to determine if they're stacked on top of the frontendDB */
1339                 if ( be->bd_info == frontendDB->bd_info || SLAP_ISGLOBALOVERLAY( be ) ) {
1340                         isglobal = 1;
1341                         if ( on->on_bi.bi_flags & SLAPO_BFLAG_DBONLY ) {
1342                                 Debug( LDAP_DEBUG_ANY, "overlay_config(): "
1343                                         "overlay \"%s\" cannot be global.\n",
1344                                         ov, 0, 0 );
1345                                 return 1;
1346                         }
1347
1348                 } else if ( on->on_bi.bi_flags & SLAPO_BFLAG_GLOBONLY ) {
1349                         Debug( LDAP_DEBUG_ANY, "overlay_config(): "
1350                                 "overlay \"%s\" can only be global.\n",
1351                                 ov, 0, 0 );
1352                         return 1;
1353                 }
1354
1355                 oi = ch_malloc( sizeof( slap_overinfo ) );
1356                 oi->oi_orig = be->bd_info;
1357                 oi->oi_bi = *be->bd_info;
1358                 oi->oi_origdb = be;
1359
1360                 if ( isglobal ) {
1361                         SLAP_DBFLAGS( be ) |= SLAP_DBFLAG_GLOBAL_OVERLAY;
1362                 }
1363
1364                 /* Save a pointer to ourself in bi_private.
1365                  */
1366                 oi->oi_bi.bi_private = oi;
1367                 oi->oi_list = NULL;
1368                 bi = (BackendInfo *)oi;
1369
1370                 bi->bi_type = (char *)overtype;
1371
1372                 bi->bi_db_config = over_db_config;
1373                 bi->bi_db_open = over_db_open;
1374                 bi->bi_db_close = over_db_close;
1375                 bi->bi_db_destroy = over_db_destroy;
1376
1377                 bi->bi_op_bind = over_op_bind;
1378                 bi->bi_op_unbind = over_op_unbind;
1379                 bi->bi_op_search = over_op_search;
1380                 bi->bi_op_compare = over_op_compare;
1381                 bi->bi_op_modify = over_op_modify;
1382                 bi->bi_op_modrdn = over_op_modrdn;
1383                 bi->bi_op_add = over_op_add;
1384                 bi->bi_op_delete = over_op_delete;
1385                 bi->bi_op_abandon = over_op_abandon;
1386                 bi->bi_op_cancel = over_op_cancel;
1387
1388                 bi->bi_extended = over_op_extended;
1389
1390                 /*
1391                  * this is fine because it has the same
1392                  * args of the operations; we need to rework
1393                  * all the hooks to share the same args
1394                  * of the operations...
1395                  */
1396                 bi->bi_operational = over_aux_operational;
1397                 bi->bi_chk_referrals = over_aux_chk_referrals;
1398                 bi->bi_chk_controls = over_aux_chk_controls;
1399
1400                 /* these have specific arglists */
1401                 bi->bi_entry_get_rw = over_entry_get_rw;
1402                 bi->bi_entry_release_rw = over_entry_release_rw;
1403                 bi->bi_access_allowed = over_access_allowed;
1404                 bi->bi_acl_group = over_acl_group;
1405                 bi->bi_acl_attribute = over_acl_attribute;
1406
1407                 bi->bi_connection_init = over_connection_init;
1408                 bi->bi_connection_destroy = over_connection_destroy;
1409
1410                 be->bd_info = bi;
1411
1412         } else {
1413                 if ( overlay_is_inst( be, ov ) ) {
1414                         if ( SLAPO_SINGLE( be ) ) {
1415                                 Debug( LDAP_DEBUG_ANY, "overlay_config(): "
1416                                         "overlay \"%s\" already in list\n",
1417                                         ov, 0, 0 );
1418                                 return 1;
1419                         }
1420                 }
1421
1422                 oi = be->bd_info->bi_private;
1423         }
1424
1425         /* Insert new overlay into list. By default overlays are
1426          * added to head of list and executed in LIFO order.
1427          */
1428         on2 = ch_calloc( 1, sizeof(slap_overinst) );
1429         *on2 = *on;
1430         on2->on_info = oi;
1431
1432         prev = &oi->oi_list;
1433         /* Do we need to find the insertion point? */
1434         if ( idx >= 0 ) {
1435                 int i;
1436
1437                 /* count current overlays */
1438                 for ( i=0, on=oi->oi_list; on; on=on->on_next, i++ );
1439
1440                 /* are we just appending a new one? */
1441                 if ( idx >= i )
1442                         idx = -1;
1443         }
1444         overlay_insert( be, on2, &prev, idx );
1445
1446         /* Any initialization needed? */
1447         if ( on2->on_bi.bi_db_init ) {
1448                 int rc;
1449                 be->bd_info = (BackendInfo *)on2;
1450                 rc = on2->on_bi.bi_db_init( be, cr);
1451                 be->bd_info = (BackendInfo *)oi;
1452                 if ( rc ) {
1453                         *prev = on2->on_next;
1454                         ch_free( on2 );
1455                         on2 = NULL;
1456                         return rc;
1457                 }
1458         }
1459
1460         if ( res )
1461                 *res = &on2->on_bi;
1462
1463         return 0;
1464 }