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 2003-2015 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                 db.bd_info = &on->on_bi;
 154                 if ( db.bd_info->bi_db_open ) {
 155                         rc = db.bd_info->bi_db_open( &db, cr );
 156                 }
 157         }
 158
 159         return rc;
 160 }
 161
 162 static int
 163 over_db_close(
 164         BackendDB *be,
 165         ConfigReply *cr
 166 )
 167 {
 168         slap_overinfo *oi = be->bd_info->bi_private;
 169         slap_overinst *on = oi->oi_list;
 170         BackendInfo *bi_orig = be->bd_info;
 171         int rc = 0;
 172
 173         for (; on && rc == 0; on=on->on_next) {
 174                 be->bd_info = &on->on_bi;
 175                 if ( be->bd_info->bi_db_close ) {
 176                         rc = be->bd_info->bi_db_close( be, cr );
 177                 }
 178         }
 179
 180         if ( oi->oi_orig->bi_db_close ) {
 181                 be->bd_info = oi->oi_orig;
 182                 rc = be->bd_info->bi_db_close( be, cr );
 183         }
 184
 185         be->bd_info = bi_orig;
 186         return rc;
 187 }
 188
 189 static int
 190 over_db_destroy(
 191         BackendDB *be,
 192         ConfigReply *cr
 193 )
 194 {
 195         slap_overinfo *oi = be->bd_info->bi_private;
 196         slap_overinst *on = oi->oi_list, *next;
 197         BackendInfo *bi_orig = be->bd_info;
 198         int rc = 0;
 199
 200         be->bd_info = oi->oi_orig;
 201         if ( be->bd_info->bi_db_destroy ) {
 202                 rc = be->bd_info->bi_db_destroy( be, cr );
 203         }
 204
 205         for (; on && rc == 0; on=on->on_next) {
 206                 be->bd_info = &on->on_bi;
 207                 if ( be->bd_info->bi_db_destroy ) {
 208                         rc = be->bd_info->bi_db_destroy( be, cr );
 209                 }
 210         }
 211
 212         on = oi->oi_list;
 213         if ( on ) {
 214                 for (next = on->on_next; on; on=next) {
 215                         next = on->on_next;
 216                         free( on );
 217                 }
 218         }
 219         be->bd_info = bi_orig;
 220         free( oi );
 221         return rc;
 222 }
 223
 224 static int
 225 over_back_response ( Operation *op, SlapReply *rs )
 226 {
 227         slap_overinfo *oi = op->o_callback->sc_private;
 228         slap_overinst *on = oi->oi_list;
 229         int rc = SLAP_CB_CONTINUE;
 230         BackendDB *be = op->o_bd, db = *op->o_bd;
 231
 232         db.be_flags |= SLAP_DBFLAG_OVERLAY;
 233         op->o_bd = &db;
 234         for (; on; on=on->on_next ) {
 235                 if ( on->on_response ) {
 236                         db.bd_info = (BackendInfo *)on;
 237                         rc = on->on_response( op, rs );
 238                         if ( rc != SLAP_CB_CONTINUE ) break;
 239                 }
 240         }
 241         /* Bypass the remaining on_response layers, but allow
 242          * normal execution to continue.
 243          */
 244         if ( rc == SLAP_CB_BYPASS )
 245                 rc = SLAP_CB_CONTINUE;
 246         op->o_bd = be;
 247         return rc;
 248 }
 249
 250 static int
 251 over_access_allowed(
 252         Operation               *op,
 253         Entry                   *e,
 254         AttributeDescription    *desc,
 255         struct berval           *val,
 256         slap_access_t           access,
 257         AccessControlState      *state,
 258         slap_mask_t             *maskp )
 259 {
 260         slap_overinfo *oi;
 261         slap_overinst *on;
 262         BackendInfo *bi;
 263         BackendDB *be = op->o_bd, db;
 264         int rc = SLAP_CB_CONTINUE;
 265
 266         /* FIXME: used to happen for instance during abandon
 267          * when global overlays are used... */
 268         assert( op->o_bd != NULL );
 269
 270         bi = op->o_bd->bd_info;
 271         /* Were we invoked on the frontend? */
 272         if ( !bi->bi_access_allowed ) {
 273                 oi = frontendDB->bd_info->bi_private;
 274         } else {
 275                 oi = op->o_bd->bd_info->bi_private;
 276         }
 277         on = oi->oi_list;
 278
 279         for ( ; on; on = on->on_next ) {
 280                 if ( on->on_bi.bi_access_allowed ) {
 281                         /* NOTE: do not copy the structure until required */
 282                         if ( !SLAP_ISOVERLAY( op->o_bd ) ) {
 283                                 db = *op->o_bd;
 284                                 db.be_flags |= SLAP_DBFLAG_OVERLAY;
 285                                 op->o_bd = &db;
 286                         }
 287
 288                         op->o_bd->bd_info = (BackendInfo *)on;
 289                         rc = on->on_bi.bi_access_allowed( op, e,
 290                                 desc, val, access, state, maskp );
 291                         if ( rc != SLAP_CB_CONTINUE ) break;
 292                 }
 293         }
 294
 295         if ( rc == SLAP_CB_CONTINUE ) {
 296                 BI_access_allowed       *bi_access_allowed;
 297
 298                 /* if the database structure was changed, o_bd points to a
 299                  * copy of the structure; put the original bd_info in place */
 300                 if ( SLAP_ISOVERLAY( op->o_bd ) ) {
 301                         op->o_bd->bd_info = oi->oi_orig;
 302                 }
 303
 304                 if ( oi->oi_orig->bi_access_allowed ) {
 305                         bi_access_allowed = oi->oi_orig->bi_access_allowed;
 306                 } else {
 307                         bi_access_allowed = slap_access_allowed;
 308                 }
 309
 310                 rc = bi_access_allowed( op, e,
 311                         desc, val, access, state, maskp );
 312         }
 313         /* should not fall thru this far without anything happening... */
 314         if ( rc == SLAP_CB_CONTINUE ) {
 315                 /* access not allowed */
 316                 rc = 0;
 317         }
 318
 319         op->o_bd = be;
 320         op->o_bd->bd_info = bi;
 321
 322         return rc;
 323 }
 324
 325 int
 326 overlay_entry_get_ov(
 327         Operation               *op,
 328         struct berval   *dn,
 329         ObjectClass             *oc,
 330         AttributeDescription    *ad,
 331         int     rw,
 332         Entry   **e,
 333         slap_overinst *on )
 334 {
 335         slap_overinfo *oi = on->on_info;
 336         BackendDB *be = op->o_bd, db;
 337         BackendInfo *bi = op->o_bd->bd_info;
 338         int rc = SLAP_CB_CONTINUE;
 339
 340         for ( ; on; on = on->on_next ) {
 341                 if ( on->on_bi.bi_entry_get_rw ) {
 342                         /* NOTE: do not copy the structure until required */
 343                         if ( !SLAP_ISOVERLAY( op->o_bd ) ) {
 344                                 db = *op->o_bd;
 345                                 db.be_flags |= SLAP_DBFLAG_OVERLAY;
 346                                 op->o_bd = &db;
 347                         }
 348
 349                         op->o_bd->bd_info = (BackendInfo *)on;
 350                         rc = on->on_bi.bi_entry_get_rw( op, dn,
 351                                 oc, ad, rw, e );
 352                         if ( rc != SLAP_CB_CONTINUE ) break;
 353                 }
 354         }
 355
 356         if ( rc == SLAP_CB_CONTINUE ) {
 357                 /* if the database structure was changed, o_bd points to a
 358                  * copy of the structure; put the original bd_info in place */
 359                 if ( SLAP_ISOVERLAY( op->o_bd ) ) {
 360                         op->o_bd->bd_info = oi->oi_orig;
 361                 }
 362
 363                 if ( oi->oi_orig->bi_entry_get_rw ) {
 364                         rc = oi->oi_orig->bi_entry_get_rw( op, dn,
 365                                 oc, ad, rw, e );
 366                 }
 367         }
 368         /* should not fall thru this far without anything happening... */
 369         if ( rc == SLAP_CB_CONTINUE ) {
 370                 rc = LDAP_UNWILLING_TO_PERFORM;
 371         }
 372
 373         op->o_bd = be;
 374         op->o_bd->bd_info = bi;
 375
 376         return rc;
 377 }
 378
 379 static int
 380 over_entry_get_rw(
 381         Operation               *op,
 382         struct berval   *dn,
 383         ObjectClass             *oc,
 384         AttributeDescription    *ad,
 385         int     rw,
 386         Entry   **e )
 387 {
 388         slap_overinfo *oi;
 389         slap_overinst *on;
 390
 391         assert( op->o_bd != NULL );
 392
 393         oi = op->o_bd->bd_info->bi_private;
 394         on = oi->oi_list;
 395
 396         return overlay_entry_get_ov( op, dn, oc, ad, rw, e, on );
 397 }
 398
 399 int
 400 overlay_entry_release_ov(
 401         Operation       *op,
 402         Entry   *e,
 403         int rw,
 404         slap_overinst *on )
 405 {
 406         slap_overinfo *oi = on->on_info;
 407         BackendDB *be = op->o_bd, db;
 408         BackendInfo *bi = op->o_bd->bd_info;
 409         int rc = SLAP_CB_CONTINUE;
 410
 411         for ( ; on; on = on->on_next ) {
 412                 if ( on->on_bi.bi_entry_release_rw ) {
 413                         /* NOTE: do not copy the structure until required */
 414                         if ( !SLAP_ISOVERLAY( op->o_bd ) ) {
 415                                 db = *op->o_bd;
 416                                 db.be_flags |= SLAP_DBFLAG_OVERLAY;
 417                                 op->o_bd = &db;
 418                         }
 419
 420                         op->o_bd->bd_info = (BackendInfo *)on;
 421                         rc = on->on_bi.bi_entry_release_rw( op, e, rw );
 422                         if ( rc != SLAP_CB_CONTINUE ) break;
 423                 }
 424         }
 425
 426         if ( rc == SLAP_CB_CONTINUE ) {
 427                 /* if the database structure was changed, o_bd points to a
 428                  * copy of the structure; put the original bd_info in place */
 429                 if ( SLAP_ISOVERLAY( op->o_bd ) ) {
 430                         op->o_bd->bd_info = oi->oi_orig;
 431                 }
 432
 433                 if ( oi->oi_orig->bi_entry_release_rw ) {
 434                         rc = oi->oi_orig->bi_entry_release_rw( op, e, rw );
 435                 }
 436         }
 437         /* should not fall thru this far without anything happening... */
 438         if ( rc == SLAP_CB_CONTINUE ) {
 439                 entry_free( e );
 440                 rc = 0;
 441         }
 442
 443         op->o_bd = be;
 444         op->o_bd->bd_info = bi;
 445
 446         return rc;
 447 }
 448
 449 static int
 450 over_entry_release_rw(
 451         Operation       *op,
 452         Entry   *e,
 453         int rw )
 454 {
 455         slap_overinfo *oi;
 456         slap_overinst *on;
 457
 458         assert( op->o_bd != NULL );
 459
 460         oi = op->o_bd->bd_info->bi_private;
 461         on = oi->oi_list;
 462
 463         return overlay_entry_release_ov( op, e, rw, on );
 464 }
 465
 466 static int
 467 over_acl_group(
 468         Operation               *op,
 469         Entry                   *e,
 470         struct berval           *gr_ndn,
 471         struct berval           *op_ndn,
 472         ObjectClass             *group_oc,
 473         AttributeDescription    *group_at )
 474 {
 475         slap_overinfo *oi;
 476         slap_overinst *on;
 477         BackendInfo *bi;
 478         BackendDB *be = op->o_bd, db;
 479         int rc = SLAP_CB_CONTINUE;
 480
 481         /* FIXME: used to happen for instance during abandon
 482          * when global overlays are used... */
 483         assert( be != NULL );
 484
 485         bi = be->bd_info;
 486         oi = bi->bi_private;
 487         on = oi->oi_list;
 488
 489         for ( ; on; on = on->on_next ) {
 490                 if ( on->on_bi.bi_acl_group ) {
 491                         /* NOTE: do not copy the structure until required */
 492                         if ( !SLAP_ISOVERLAY( op->o_bd ) ) {
 493                                 db = *op->o_bd;
 494                                 db.be_flags |= SLAP_DBFLAG_OVERLAY;
 495                                 op->o_bd = &db;
 496                         }
 497
 498                         op->o_bd->bd_info = (BackendInfo *)on;
 499                         rc = on->on_bi.bi_acl_group( op, e,
 500                                 gr_ndn, op_ndn, group_oc, group_at );
 501                         if ( rc != SLAP_CB_CONTINUE ) break;
 502                 }
 503         }
 504
 505         if ( rc == SLAP_CB_CONTINUE ) {
 506                 BI_acl_group            *bi_acl_group;
 507
 508                 /* if the database structure was changed, o_bd points to a
 509                  * copy of the structure; put the original bd_info in place */
 510                 if ( SLAP_ISOVERLAY( op->o_bd ) ) {
 511                         op->o_bd->bd_info = oi->oi_orig;
 512                 }
 513
 514                 if ( oi->oi_orig->bi_acl_group ) {
 515                         bi_acl_group = oi->oi_orig->bi_acl_group;
 516                 } else {
 517                         bi_acl_group = backend_group;
 518                 }
 519
 520                 rc = bi_acl_group( op, e,
 521                         gr_ndn, op_ndn, group_oc, group_at );
 522         }
 523         /* should not fall thru this far without anything happening... */
 524         if ( rc == SLAP_CB_CONTINUE ) {
 525                 /* access not allowed */
 526                 rc = 0;
 527         }
 528
 529         op->o_bd = be;
 530         op->o_bd->bd_info = bi;
 531
 532         return rc;
 533 }
 534
 535 static int
 536 over_acl_attribute(
 537         Operation               *op,
 538         Entry                   *target,
 539         struct berval           *entry_ndn,
 540         AttributeDescription    *entry_at,
 541         BerVarray               *vals,
 542         slap_access_t           access )
 543 {
 544         slap_overinfo *oi;
 545         slap_overinst *on;
 546         BackendInfo *bi;
 547         BackendDB *be = op->o_bd, db;
 548         int rc = SLAP_CB_CONTINUE;
 549
 550         /* FIXME: used to happen for instance during abandon
 551          * when global overlays are used... */
 552         assert( be != NULL );
 553
 554         bi = be->bd_info;
 555         oi = bi->bi_private;
 556         on = oi->oi_list;
 557
 558         for ( ; on; on = on->on_next ) {
 559                 if ( on->on_bi.bi_acl_attribute ) {
 560                         /* NOTE: do not copy the structure until required */
 561                         if ( !SLAP_ISOVERLAY( op->o_bd ) ) {
 562                                 db = *op->o_bd;
 563                                 db.be_flags |= SLAP_DBFLAG_OVERLAY;
 564                                 op->o_bd = &db;
 565                         }
 566
 567                         op->o_bd->bd_info = (BackendInfo *)on;
 568                         rc = on->on_bi.bi_acl_attribute( op, target,
 569                                 entry_ndn, entry_at, vals, access );
 570                         if ( rc != SLAP_CB_CONTINUE ) break;
 571                 }
 572         }
 573
 574         if ( rc == SLAP_CB_CONTINUE ) {
 575                 BI_acl_attribute                *bi_acl_attribute;
 576
 577                 /* if the database structure was changed, o_bd points to a
 578                  * copy of the structure; put the original bd_info in place */
 579                 if ( SLAP_ISOVERLAY( op->o_bd ) ) {
 580                         op->o_bd->bd_info = oi->oi_orig;
 581                 }
 582
 583                 if ( oi->oi_orig->bi_acl_attribute ) {
 584                         bi_acl_attribute = oi->oi_orig->bi_acl_attribute;
 585                 } else {
 586                         bi_acl_attribute = backend_attribute;
 587                 }
 588
 589                 rc = bi_acl_attribute( op, target,
 590                         entry_ndn, entry_at, vals, access );
 591         }
 592         /* should not fall thru this far without anything happening... */
 593         if ( rc == SLAP_CB_CONTINUE ) {
 594                 /* access not allowed */
 595                 rc = 0;
 596         }
 597
 598         op->o_bd = be;
 599         op->o_bd->bd_info = bi;
 600
 601         return rc;
 602 }
 603
 604 int
 605 overlay_callback_after_backover( Operation *op, slap_callback *sc, int append )
 606 {
 607         slap_callback **scp;
 608
 609         for ( scp = &op->o_callback; *scp != NULL; scp = &(*scp)->sc_next ) {
 610                 if ( (*scp)->sc_response == over_back_response ) {
 611                         sc->sc_next = (*scp)->sc_next;
 612                         (*scp)->sc_next = sc;
 613                         return 0;
 614                 }
 615         }
 616
 617         if ( append ) {
 618                 *scp = sc;
 619                 return 0;
 620         }
 621
 622         return 1;
 623 }
 624
 625 /*
 626  * default return code in case of missing backend function
 627  * and overlay stack returning SLAP_CB_CONTINUE
 628  */
 629 static int op_rc[ op_last ] = {
 630         LDAP_UNWILLING_TO_PERFORM,      /* bind */
 631         LDAP_UNWILLING_TO_PERFORM,      /* unbind */
 632         LDAP_UNWILLING_TO_PERFORM,      /* search */
 633         SLAP_CB_CONTINUE,               /* compare; pass to frontend */
 634         LDAP_UNWILLING_TO_PERFORM,      /* modify */
 635         LDAP_UNWILLING_TO_PERFORM,      /* modrdn */
 636         LDAP_UNWILLING_TO_PERFORM,      /* add */
 637         LDAP_UNWILLING_TO_PERFORM,      /* delete */
 638         LDAP_UNWILLING_TO_PERFORM,      /* abandon */
 639         LDAP_UNWILLING_TO_PERFORM,      /* cancel */
 640         LDAP_UNWILLING_TO_PERFORM,      /* extended */
 641         LDAP_SUCCESS,                   /* aux_operational */
 642         LDAP_SUCCESS,                   /* aux_chk_referrals */
 643         SLAP_CB_CONTINUE                /* aux_chk_controls; pass to frontend */
 644 };
 645
 646 int overlay_op_walk(
 647         Operation *op,
 648         SlapReply *rs,
 649         slap_operation_t which,
 650         slap_overinfo *oi,
 651         slap_overinst *on
 652 )
 653 {
 654         BI_op_bind **func;
 655         int rc = SLAP_CB_CONTINUE;
 656
 657         for (; on; on=on->on_next ) {
 658                 func = &on->on_bi.bi_op_bind;
 659                 if ( func[which] ) {
 660                         op->o_bd->bd_info = (BackendInfo *)on;
 661                         rc = func[which]( op, rs );
 662                         if ( rc != SLAP_CB_CONTINUE ) break;
 663                 }
 664         }
 665         if ( rc == SLAP_CB_BYPASS )
 666                 rc = SLAP_CB_CONTINUE;
 667
 668         /* if an overlay halted processing, make sure
 669          * any previously set cleanup handlers are run
 670          */
 671         if ( rc != SLAP_CB_CONTINUE )
 672                 goto cleanup;
 673
 674         func = &oi->oi_orig->bi_op_bind;
 675         if ( func[which] ) {
 676                 op->o_bd->bd_info = oi->oi_orig;
 677                 rc = func[which]( op, rs );
 678         }
 679         /* should not fall thru this far without anything happening... */
 680         if ( rc == SLAP_CB_CONTINUE ) {
 681                 rc = op_rc[ which ];
 682         }
 683
 684         /* The underlying backend didn't handle the request, make sure
 685          * overlay cleanup is processed.
 686          */
 687         if ( rc == LDAP_UNWILLING_TO_PERFORM ) {
 688                 slap_callback *sc_next;
 689 cleanup:
 690                 for ( ; op->o_callback && op->o_callback->sc_response !=
 691                         over_back_response; op->o_callback = sc_next ) {
 692                         sc_next = op->o_callback->sc_next;
 693                         if ( op->o_callback->sc_cleanup ) {
 694                                 op->o_callback->sc_cleanup( op, rs );
 695                         }
 696                 }
 697         }
 698         return rc;
 699 }
 700
 701 static int
 702 over_op_func(
 703         Operation *op,
 704         SlapReply *rs,
 705         slap_operation_t which
 706 )
 707 {
 708         slap_overinfo *oi;
 709         slap_overinst *on;
 710         BackendDB *be = op->o_bd, db;
 711         slap_callback cb = {NULL, over_back_response, NULL, NULL}, **sc;
 712         int rc = SLAP_CB_CONTINUE;
 713
 714         /* FIXME: used to happen for instance during abandon
 715          * when global overlays are used... */
 716         assert( op->o_bd != NULL );
 717
 718         oi = op->o_bd->bd_info->bi_private;
 719         on = oi->oi_list;
 720
 721         if ( !SLAP_ISOVERLAY( op->o_bd )) {
 722                 db = *op->o_bd;
 723                 db.be_flags |= SLAP_DBFLAG_OVERLAY;
 724                 op->o_bd = &db;
 725         }
 726         cb.sc_next = op->o_callback;
 727         cb.sc_private = oi;
 728         op->o_callback = &cb;
 729
 730         rc = overlay_op_walk( op, rs, which, oi, on );
 731         for ( sc = &op->o_callback; *sc; sc = &(*sc)->sc_next ) {
 732                 if ( *sc == &cb ) {
 733                         *sc = cb.sc_next;
 734                         break;
 735                 }
 736         }
 737
 738         op->o_bd = be;
 739         return rc;
 740 }
 741
 742 static int
 743 over_op_bind( Operation *op, SlapReply *rs )
 744 {
 745         return over_op_func( op, rs, op_bind );
 746 }
 747
 748 static int
 749 over_op_unbind( Operation *op, SlapReply *rs )
 750 {
 751         return over_op_func( op, rs, op_unbind );
 752 }
 753
 754 static int
 755 over_op_search( Operation *op, SlapReply *rs )
 756 {
 757         return over_op_func( op, rs, op_search );
 758 }
 759
 760 static int
 761 over_op_compare( Operation *op, SlapReply *rs )
 762 {
 763         return over_op_func( op, rs, op_compare );
 764 }
 765
 766 static int
 767 over_op_modify( Operation *op, SlapReply *rs )
 768 {
 769         return over_op_func( op, rs, op_modify );
 770 }
 771
 772 static int
 773 over_op_modrdn( Operation *op, SlapReply *rs )
 774 {
 775         return over_op_func( op, rs, op_modrdn );
 776 }
 777
 778 static int
 779 over_op_add( Operation *op, SlapReply *rs )
 780 {
 781         return over_op_func( op, rs, op_add );
 782 }
 783
 784 static int
 785 over_op_delete( Operation *op, SlapReply *rs )
 786 {
 787         return over_op_func( op, rs, op_delete );
 788 }
 789
 790 static int
 791 over_op_abandon( Operation *op, SlapReply *rs )
 792 {
 793         return over_op_func( op, rs, op_abandon );
 794 }
 795
 796 static int
 797 over_op_cancel( Operation *op, SlapReply *rs )
 798 {
 799         return over_op_func( op, rs, op_cancel );
 800 }
 801
 802 static int
 803 over_op_extended( Operation *op, SlapReply *rs )
 804 {
 805         return over_op_func( op, rs, op_extended );
 806 }
 807
 808 static int
 809 over_aux_operational( Operation *op, SlapReply *rs )
 810 {
 811         return over_op_func( op, rs, op_aux_operational );
 812 }
 813
 814 static int
 815 over_aux_chk_referrals( Operation *op, SlapReply *rs )
 816 {
 817         return over_op_func( op, rs, op_aux_chk_referrals );
 818 }
 819
 820 static int
 821 over_aux_chk_controls( Operation *op, SlapReply *rs )
 822 {
 823         return over_op_func( op, rs, op_aux_chk_controls );
 824 }
 825
 826 enum conn_which {
 827         conn_init = 0,
 828         conn_destroy,
 829         conn_last
 830 };
 831
 832 static int
 833 over_connection_func(
 834         BackendDB       *bd,
 835         Connection      *conn,
 836         enum conn_which which
 837 )
 838 {
 839         slap_overinfo           *oi;
 840         slap_overinst           *on;
 841         BackendDB               db;
 842         int                     rc = SLAP_CB_CONTINUE;
 843         BI_connection_init      **func;
 844
 845         /* FIXME: used to happen for instance during abandon
 846          * when global overlays are used... */
 847         assert( bd != NULL );
 848
 849         oi = bd->bd_info->bi_private;
 850         on = oi->oi_list;
 851
 852         if ( !SLAP_ISOVERLAY( bd ) ) {
 853                 db = *bd;
 854                 db.be_flags |= SLAP_DBFLAG_OVERLAY;
 855                 bd = &db;
 856         }
 857
 858         for ( ; on; on = on->on_next ) {
 859                 func = &on->on_bi.bi_connection_init;
 860                 if ( func[ which ] ) {
 861                         bd->bd_info = (BackendInfo *)on;
 862                         rc = func[ which ]( bd, conn );
 863                         if ( rc != SLAP_CB_CONTINUE ) break;
 864                 }
 865         }
 866
 867         func = &oi->oi_orig->bi_connection_init;
 868         if ( func[ which ] && rc == SLAP_CB_CONTINUE ) {
 869                 bd->bd_info = oi->oi_orig;
 870                 rc = func[ which ]( bd, conn );
 871         }
 872         /* should not fall thru this far without anything happening... */
 873         if ( rc == SLAP_CB_CONTINUE ) {
 874                 rc = LDAP_UNWILLING_TO_PERFORM;
 875         }
 876
 877         return rc;
 878 }
 879
 880 static int
 881 over_connection_init(
 882         BackendDB       *bd,
 883         Connection      *conn
 884 )
 885 {
 886         return over_connection_func( bd, conn, conn_init );
 887 }
 888
 889 static int
 890 over_connection_destroy(
 891         BackendDB       *bd,
 892         Connection      *conn
 893 )
 894 {
 895         return over_connection_func( bd, conn, conn_destroy );
 896 }
 897
 898 int
 899 overlay_register(
 900         slap_overinst *on
 901 )
 902 {
 903         slap_overinst   *tmp;
 904
 905         /* FIXME: check for duplicates? */
 906         for ( tmp = overlays; tmp != NULL; tmp = tmp->on_next ) {
 907                 if ( strcmp( on->on_bi.bi_type, tmp->on_bi.bi_type ) == 0 ) {
 908                         Debug( LDAP_DEBUG_ANY,
 909                                 "overlay_register(\"%s\"): "
 910                                 "name already in use.\n",
 911                                 on->on_bi.bi_type, 0, 0 );
 912                         return -1;
 913                 }
 914
 915                 if ( on->on_bi.bi_obsolete_names != NULL ) {
 916                         int     i;
 917
 918                         for ( i = 0; on->on_bi.bi_obsolete_names[ i ] != NULL; i++ ) {
 919                                 if ( strcmp( on->on_bi.bi_obsolete_names[ i ], tmp->on_bi.bi_type ) == 0 ) {
 920                                         Debug( LDAP_DEBUG_ANY,
 921                                                 "overlay_register(\"%s\"): "
 922                                                 "obsolete name \"%s\" already in use "
 923                                                 "by overlay \"%s\".\n",
 924                                                 on->on_bi.bi_type,
 925                                                 on->on_bi.bi_obsolete_names[ i ],
 926                                                 tmp->on_bi.bi_type );
 927                                         return -1;
 928                                 }
 929                         }
 930                 }
 931
 932                 if ( tmp->on_bi.bi_obsolete_names != NULL ) {
 933                         int     i;
 934
 935                         for ( i = 0; tmp->on_bi.bi_obsolete_names[ i ] != NULL; i++ ) {
 936                                 int     j;
 937
 938                                 if ( strcmp( on->on_bi.bi_type, tmp->on_bi.bi_obsolete_names[ i ] ) == 0 ) {
 939                                         Debug( LDAP_DEBUG_ANY,
 940                                                 "overlay_register(\"%s\"): "
 941                                                 "name already in use "
 942                                                 "as obsolete by overlay \"%s\".\n",
 943                                                 on->on_bi.bi_type,
 944                                                 tmp->on_bi.bi_obsolete_names[ i ], 0 );
 945                                         return -1;
 946                                 }
 947
 948                                 if ( on->on_bi.bi_obsolete_names != NULL ) {
 949                                         for ( j = 0; on->on_bi.bi_obsolete_names[ j ] != NULL; j++ ) {
 950                                                 if ( strcmp( on->on_bi.bi_obsolete_names[ j ], tmp->on_bi.bi_obsolete_names[ i ] ) == 0 ) {
 951                                                         Debug( LDAP_DEBUG_ANY,
 952                                                                 "overlay_register(\"%s\"): "
 953                                                                 "obsolete name \"%s\" already in use "
 954                                                                 "as obsolete by overlay \"%s\".\n",
 955                                                                 on->on_bi.bi_type,
 956                                                                 on->on_bi.bi_obsolete_names[ j ],
 957                                                                 tmp->on_bi.bi_type );
 958                                                         return -1;
 959                                                 }
 960                                         }
 961                                 }
 962                         }
 963                 }
 964         }
 965
 966         on->on_next = overlays;
 967         overlays = on;
 968         return 0;
 969 }
 970
 971 /*
 972  * iterator on registered overlays; overlay_next( NULL ) returns the first
 973  * overlay; subsequent calls with the previously returned value allow to
 974  * iterate over the entire list; returns NULL when no more overlays are
 975  * registered.
 976  */
 977
 978 slap_overinst *
 979 overlay_next(
 980         slap_overinst *on
 981 )
 982 {
 983         if ( on == NULL ) {
 984                 return overlays;
 985         }
 986
 987         return on->on_next;
 988 }
 989
 990 /*
 991  * returns a specific registered overlay based on the type; NULL if not
 992  * registered.
 993  */
 994
 995 slap_overinst *
 996 overlay_find( const char *over_type )
 997 {
 998         slap_overinst *on = overlays;
 999
1000         assert( over_type != NULL );
1001
1002         for ( ; on; on = on->on_next ) {
1003                 if ( strcmp( on->on_bi.bi_type, over_type ) == 0 ) {
1004                         goto foundit;
1005                 }
1006
1007                 if ( on->on_bi.bi_obsolete_names != NULL ) {
1008                         int     i;
1009
1010                         for ( i = 0; on->on_bi.bi_obsolete_names[ i ] != NULL; i++ ) {
1011                                 if ( strcmp( on->on_bi.bi_obsolete_names[ i ], over_type ) == 0 ) {
1012                                         Debug( LDAP_DEBUG_ANY,
1013                                                 "overlay_find(\"%s\"): "
1014                                                 "obsolete name for \"%s\".\n",
1015                                                 on->on_bi.bi_obsolete_names[ i ],
1016                                                 on->on_bi.bi_type, 0 );
1017                                         goto foundit;
1018                                 }
1019                         }
1020                 }
1021         }
1022
1023 foundit:;
1024         return on;
1025 }
1026
1027 static const char overtype[] = "over";
1028
1029 /*
1030  * returns TRUE (1) if the database is actually an overlay instance;
1031  * FALSE (0) otherwise.
1032  */
1033
1034 int
1035 overlay_is_over( BackendDB *be )
1036 {
1037         return be->bd_info->bi_type == overtype;
1038 }
1039
1040 /*
1041  * returns TRUE (1) if the given database is actually an overlay
1042  * instance and, somewhere in the list, contains the requested overlay;
1043  * FALSE (0) otherwise.
1044  */
1045
1046 int
1047 overlay_is_inst( BackendDB *be, const char *over_type )
1048 {
1049         slap_overinst   *on;
1050
1051         assert( be != NULL );
1052
1053         if ( !overlay_is_over( be ) ) {
1054                 return 0;
1055         }
1056
1057         on = ((slap_overinfo *)be->bd_info->bi_private)->oi_list;
1058         for ( ; on; on = on->on_next ) {
1059                 if ( strcmp( on->on_bi.bi_type, over_type ) == 0 ) {
1060                         return 1;
1061                 }
1062         }
1063
1064         return 0;
1065 }
1066
1067 int
1068 overlay_register_control( BackendDB *be, const char *oid )
1069 {
1070         int             gotit = 0;
1071         int             cid;
1072
1073         if ( slap_find_control_id( oid, &cid ) == LDAP_CONTROL_NOT_FOUND ) {
1074                 return -1;
1075         }
1076
1077         if ( SLAP_ISGLOBALOVERLAY( be ) ) {
1078                 BackendDB *bd;
1079
1080                 /* add to all backends... */
1081                 LDAP_STAILQ_FOREACH( bd, &backendDB, be_next ) {
1082                         if ( bd == be->bd_self ) {
1083                                 gotit = 1;
1084                         }
1085
1086                         /* overlays can be instanciated multiple times, use
1087                          * be_ctrls[ cid ] as an instance counter, so that the
1088                          * overlay's controls are only really disabled after the
1089                          * last instance called overlay_register_control() */
1090                         bd->be_ctrls[ cid ]++;
1091                         bd->be_ctrls[ SLAP_MAX_CIDS ] = 1;
1092                 }
1093
1094         }
1095
1096         if ( !gotit ) {
1097                 /* overlays can be instanciated multiple times, use
1098                  * be_ctrls[ cid ] as an instance counter, so that the
1099                  * overlay's controls are only really unregistered after the
1100                  * last instance called overlay_register_control() */
1101                 be->bd_self->be_ctrls[ cid ]++;
1102                 be->bd_self->be_ctrls[ SLAP_MAX_CIDS ] = 1;
1103         }
1104
1105         return 0;
1106 }
1107
1108 #ifdef SLAP_CONFIG_DELETE
1109 void
1110 overlay_unregister_control( BackendDB *be, const char *oid )
1111 {
1112         int             gotit = 0;
1113         int             cid;
1114
1115         if ( slap_find_control_id( oid, &cid ) == LDAP_CONTROL_NOT_FOUND ) {
1116                 return;
1117         }
1118
1119         if ( SLAP_ISGLOBALOVERLAY( be ) ) {
1120                 BackendDB *bd;
1121
1122                 /* remove from all backends... */
1123                 LDAP_STAILQ_FOREACH( bd, &backendDB, be_next ) {
1124                         if ( bd == be->bd_self ) {
1125                                 gotit = 1;
1126                         }
1127
1128                         bd->be_ctrls[ cid ]--;
1129                 }
1130         }
1131
1132         if ( !gotit ) {
1133                 be->bd_self->be_ctrls[ cid ]--;
1134         }
1135 }
1136 #endif /* SLAP_CONFIG_DELETE */
1137
1138 void
1139 overlay_destroy_one( BackendDB *be, slap_overinst *on )
1140 {
1141         slap_overinfo *oi = on->on_info;
1142         slap_overinst **oidx;
1143
1144         for ( oidx = &oi->oi_list; *oidx; oidx = &(*oidx)->on_next ) {
1145                 if ( *oidx == on ) {
1146                         *oidx = on->on_next;
1147                         if ( on->on_bi.bi_db_destroy ) {
1148                                 BackendInfo *bi_orig = be->bd_info;
1149                                 be->bd_info = (BackendInfo *)on;
1150                                 on->on_bi.bi_db_destroy( be, NULL );
1151                                 be->bd_info = bi_orig;
1152                         }
1153                         free( on );
1154                         break;
1155                 }
1156         }
1157 }
1158
1159 #ifdef SLAP_CONFIG_DELETE
1160 typedef struct ov_remove_ctx {
1161         BackendDB *be;
1162         slap_overinst *on;
1163 } ov_remove_ctx;
1164
1165 int
1166 overlay_remove_cb( Operation *op, SlapReply *rs )
1167 {
1168         ov_remove_ctx *rm_ctx = (ov_remove_ctx*) op->o_callback->sc_private;
1169         BackendInfo *bi_orig = rm_ctx->be->bd_info;
1170
1171         rm_ctx->be->bd_info = (BackendInfo*) rm_ctx->on;
1172
1173         if ( rm_ctx->on->on_bi.bi_db_close ) {
1174                 rm_ctx->on->on_bi.bi_db_close( rm_ctx->be, NULL );
1175         }
1176         if ( rm_ctx->on->on_bi.bi_db_destroy ) {
1177                 rm_ctx->on->on_bi.bi_db_destroy( rm_ctx->be, NULL );
1178         }
1179
1180         /* clean up after removing last overlay */
1181         if ( ! rm_ctx->on->on_info->oi_list ) {
1182                 /* reset db flags and bd_info to orig */
1183                 SLAP_DBFLAGS( rm_ctx->be ) &= ~SLAP_DBFLAG_GLOBAL_OVERLAY;
1184                 rm_ctx->be->bd_info = rm_ctx->on->on_info->oi_orig;
1185                 ch_free(rm_ctx->on->on_info);
1186         } else {
1187                 rm_ctx->be->bd_info = bi_orig;
1188         }
1189         free( rm_ctx->on );
1190         op->o_tmpfree(rm_ctx, op->o_tmpmemctx);
1191         return SLAP_CB_CONTINUE;
1192 }
1193
1194 void
1195 overlay_remove( BackendDB *be, slap_overinst *on, Operation *op )
1196 {
1197         slap_overinfo *oi = on->on_info;
1198         slap_overinst **oidx;
1199         ov_remove_ctx *rm_ctx;
1200         slap_callback *rm_cb, *cb;
1201
1202         /* remove overlay from oi_list */
1203         for ( oidx = &oi->oi_list; *oidx; oidx = &(*oidx)->on_next ) {
1204                 if ( *oidx == on ) {
1205                         *oidx = on->on_next;
1206                         break;
1207                 }
1208         }
1209
1210         /* The db_close and db_destroy handlers to cleanup a release
1211          * the overlay's resources are called from the cleanup callback
1212          */
1213         rm_ctx = op->o_tmpalloc( sizeof( ov_remove_ctx ), op->o_tmpmemctx );
1214         rm_ctx->be = be;
1215         rm_ctx->on = on;
1216
1217         rm_cb = op->o_tmpalloc( sizeof( slap_callback ), op->o_tmpmemctx );
1218         rm_cb->sc_next = NULL;
1219         rm_cb->sc_cleanup = overlay_remove_cb;
1220         rm_cb->sc_response = NULL;
1221         rm_cb->sc_private = (void*) rm_ctx;
1222
1223         /* Append callback to the end of the list */
1224         if ( !op->o_callback ) {
1225                 op->o_callback = rm_cb;
1226         } else {
1227                 for ( cb = op->o_callback; cb->sc_next; cb = cb->sc_next );
1228                 cb->sc_next = rm_cb;
1229         }
1230 }
1231 #endif /* SLAP_CONFIG_DELETE */
1232
1233 void
1234 overlay_insert( BackendDB *be, slap_overinst *on2, slap_overinst ***prev,
1235         int idx )
1236 {
1237         slap_overinfo *oi = (slap_overinfo *)be->bd_info;
1238
1239         if ( idx == -1 ) {
1240                 on2->on_next = oi->oi_list;
1241                 oi->oi_list = on2;
1242         } else {
1243                 int i, novs;
1244                 slap_overinst *on, **prev;
1245
1246                 /* Since the list is in reverse order and is singly linked,
1247                  * we have to count the overlays and then insert backwards.
1248                  * Adding on overlay at a specific point should be a pretty
1249                  * infrequent occurrence.
1250                  */
1251                 novs = 0;
1252                 for ( on = oi->oi_list; on; on=on->on_next )
1253                         novs++;
1254
1255                 if (idx > novs)
1256                         idx = 0;
1257                 else
1258                         idx = novs - idx;
1259
1260                 /* advance to insertion point */
1261                 prev = &oi->oi_list;
1262                 for ( i=0; i<idx; i++ ) {
1263                         on = *prev;
1264                         prev = &on->on_next;
1265                 }
1266                 /* insert */
1267                 on2->on_next = *prev;
1268                 *prev = on2;
1269         }
1270 }
1271
1272 void
1273 overlay_move( BackendDB *be, slap_overinst *on, int idx )
1274 {
1275         slap_overinfo *oi = (slap_overinfo *)be->bd_info;
1276         slap_overinst **onp;
1277
1278         for (onp = &oi->oi_list; *onp; onp= &(*onp)->on_next) {
1279                 if ( *onp == on ) {
1280                         *onp = on->on_next;
1281                         break;
1282                 }
1283         }
1284         overlay_insert( be, on, &onp, idx );
1285 }
1286
1287 /* add an overlay to a particular backend. */
1288 int
1289 overlay_config( BackendDB *be, const char *ov, int idx, BackendInfo **res, ConfigReply *cr )
1290 {
1291         slap_overinst *on = NULL, *on2 = NULL, **prev;
1292         slap_overinfo *oi = NULL;
1293         BackendInfo *bi = NULL;
1294
1295         if ( res )
1296                 *res = NULL;
1297
1298         on = overlay_find( ov );
1299         if ( !on ) {
1300                 Debug( LDAP_DEBUG_ANY, "overlay \"%s\" not found\n", ov, 0, 0 );
1301                 return 1;
1302         }
1303
1304         /* If this is the first overlay on this backend, set up the
1305          * overlay info structure
1306          */
1307         if ( !overlay_is_over( be ) ) {
1308                 int     isglobal = 0;
1309
1310                 /* NOTE: the first time a global overlay is configured,
1311                  * frontendDB gets this flag; it is used later by overlays
1312                  * to determine if they're stacked on top of the frontendDB */
1313                 if ( be->bd_info == frontendDB->bd_info || SLAP_ISGLOBALOVERLAY( be ) ) {
1314                         isglobal = 1;
1315                         if ( on->on_bi.bi_flags & SLAPO_BFLAG_DBONLY ) {
1316                                 Debug( LDAP_DEBUG_ANY, "overlay_config(): "
1317                                         "overlay \"%s\" cannot be global.\n",
1318                                         ov, 0, 0 );
1319                                 return 1;
1320                         }
1321
1322                 } else if ( on->on_bi.bi_flags & SLAPO_BFLAG_GLOBONLY ) {
1323                         Debug( LDAP_DEBUG_ANY, "overlay_config(): "
1324                                 "overlay \"%s\" can only be global.\n",
1325                                 ov, 0, 0 );
1326                         return 1;
1327                 }
1328
1329                 oi = ch_malloc( sizeof( slap_overinfo ) );
1330                 oi->oi_orig = be->bd_info;
1331                 oi->oi_bi = *be->bd_info;
1332                 oi->oi_origdb = be;
1333
1334                 if ( isglobal ) {
1335                         SLAP_DBFLAGS( be ) |= SLAP_DBFLAG_GLOBAL_OVERLAY;
1336                 }
1337
1338                 /* Save a pointer to ourself in bi_private.
1339                  */
1340                 oi->oi_bi.bi_private = oi;
1341                 oi->oi_list = NULL;
1342                 bi = (BackendInfo *)oi;
1343
1344                 bi->bi_type = (char *)overtype;
1345
1346                 bi->bi_db_config = over_db_config;
1347                 bi->bi_db_open = over_db_open;
1348                 bi->bi_db_close = over_db_close;
1349                 bi->bi_db_destroy = over_db_destroy;
1350
1351                 bi->bi_op_bind = over_op_bind;
1352                 bi->bi_op_unbind = over_op_unbind;
1353                 bi->bi_op_search = over_op_search;
1354                 bi->bi_op_compare = over_op_compare;
1355                 bi->bi_op_modify = over_op_modify;
1356                 bi->bi_op_modrdn = over_op_modrdn;
1357                 bi->bi_op_add = over_op_add;
1358                 bi->bi_op_delete = over_op_delete;
1359                 bi->bi_op_abandon = over_op_abandon;
1360                 bi->bi_op_cancel = over_op_cancel;
1361
1362                 bi->bi_extended = over_op_extended;
1363
1364                 /*
1365                  * this is fine because it has the same
1366                  * args of the operations; we need to rework
1367                  * all the hooks to share the same args
1368                  * of the operations...
1369                  */
1370                 bi->bi_operational = over_aux_operational;
1371                 bi->bi_chk_referrals = over_aux_chk_referrals;
1372                 bi->bi_chk_controls = over_aux_chk_controls;
1373
1374                 /* these have specific arglists */
1375                 bi->bi_entry_get_rw = over_entry_get_rw;
1376                 bi->bi_entry_release_rw = over_entry_release_rw;
1377                 bi->bi_access_allowed = over_access_allowed;
1378                 bi->bi_acl_group = over_acl_group;
1379                 bi->bi_acl_attribute = over_acl_attribute;
1380
1381                 bi->bi_connection_init = over_connection_init;
1382                 bi->bi_connection_destroy = over_connection_destroy;
1383
1384                 be->bd_info = bi;
1385
1386         } else {
1387                 if ( overlay_is_inst( be, ov ) ) {
1388                         if ( SLAPO_SINGLE( be ) ) {
1389                                 Debug( LDAP_DEBUG_ANY, "overlay_config(): "
1390                                         "overlay \"%s\" already in list\n",
1391                                         ov, 0, 0 );
1392                                 return 1;
1393                         }
1394                 }
1395
1396                 oi = be->bd_info->bi_private;
1397         }
1398
1399         /* Insert new overlay into list. By default overlays are
1400          * added to head of list and executed in LIFO order.
1401          */
1402         on2 = ch_calloc( 1, sizeof(slap_overinst) );
1403         *on2 = *on;
1404         on2->on_info = oi;
1405
1406         prev = &oi->oi_list;
1407         /* Do we need to find the insertion point? */
1408         if ( idx >= 0 ) {
1409                 int i;
1410
1411                 /* count current overlays */
1412                 for ( i=0, on=oi->oi_list; on; on=on->on_next, i++ );
1413
1414                 /* are we just appending a new one? */
1415                 if ( idx >= i )
1416                         idx = -1;
1417         }
1418         overlay_insert( be, on2, &prev, idx );
1419
1420         /* Any initialization needed? */
1421         if ( on2->on_bi.bi_db_init ) {
1422                 int rc;
1423                 be->bd_info = (BackendInfo *)on2;
1424                 rc = on2->on_bi.bi_db_init( be, cr);
1425                 be->bd_info = (BackendInfo *)oi;
1426                 if ( rc ) {
1427                         *prev = on2->on_next;
1428                         ch_free( on2 );
1429                         on2 = NULL;
1430                         return rc;
1431                 }
1432         }
1433
1434         if ( res )
1435                 *res = &on2->on_bi;
1436
1437         return 0;
1438 }
1439