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 2003-2013 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         func = &oi->oi_orig->bi_op_bind;
 669         if ( func[which] && rc == SLAP_CB_CONTINUE ) {
 670                 op->o_bd->bd_info = oi->oi_orig;
 671                 rc = func[which]( op, rs );
 672         }
 673         /* should not fall thru this far without anything happening... */
 674         if ( rc == SLAP_CB_CONTINUE ) {
 675                 rc = op_rc[ which ];
 676         }
 677
 678         /* The underlying backend didn't handle the request, make sure
 679          * overlay cleanup is processed.
 680          */
 681         if ( rc == LDAP_UNWILLING_TO_PERFORM ) {
 682                 slap_callback *sc_next;
 683                 for ( ; op->o_callback && op->o_callback->sc_response !=
 684                         over_back_response; op->o_callback = sc_next ) {
 685                         sc_next = op->o_callback->sc_next;
 686                         if ( op->o_callback->sc_cleanup ) {
 687                                 op->o_callback->sc_cleanup( op, rs );
 688                         }
 689                 }
 690         }
 691         return rc;
 692 }
 693
 694 static int
 695 over_op_func(
 696         Operation *op,
 697         SlapReply *rs,
 698         slap_operation_t which
 699 )
 700 {
 701         slap_overinfo *oi;
 702         slap_overinst *on;
 703         BackendDB *be = op->o_bd, db;
 704         slap_callback cb = {NULL, over_back_response, NULL, NULL}, **sc;
 705         int rc = SLAP_CB_CONTINUE;
 706
 707         /* FIXME: used to happen for instance during abandon
 708          * when global overlays are used... */
 709         assert( op->o_bd != NULL );
 710
 711         oi = op->o_bd->bd_info->bi_private;
 712         on = oi->oi_list;
 713
 714         if ( !SLAP_ISOVERLAY( op->o_bd )) {
 715                 db = *op->o_bd;
 716                 db.be_flags |= SLAP_DBFLAG_OVERLAY;
 717                 op->o_bd = &db;
 718         }
 719         cb.sc_next = op->o_callback;
 720         cb.sc_private = oi;
 721         op->o_callback = &cb;
 722
 723         rc = overlay_op_walk( op, rs, which, oi, on );
 724         for ( sc = &op->o_callback; *sc; sc = &(*sc)->sc_next ) {
 725                 if ( *sc == &cb ) {
 726                         *sc = cb.sc_next;
 727                         break;
 728                 }
 729         }
 730
 731         op->o_bd = be;
 732         return rc;
 733 }
 734
 735 static int
 736 over_op_bind( Operation *op, SlapReply *rs )
 737 {
 738         return over_op_func( op, rs, op_bind );
 739 }
 740
 741 static int
 742 over_op_unbind( Operation *op, SlapReply *rs )
 743 {
 744         return over_op_func( op, rs, op_unbind );
 745 }
 746
 747 static int
 748 over_op_search( Operation *op, SlapReply *rs )
 749 {
 750         return over_op_func( op, rs, op_search );
 751 }
 752
 753 static int
 754 over_op_compare( Operation *op, SlapReply *rs )
 755 {
 756         return over_op_func( op, rs, op_compare );
 757 }
 758
 759 static int
 760 over_op_modify( Operation *op, SlapReply *rs )
 761 {
 762         return over_op_func( op, rs, op_modify );
 763 }
 764
 765 static int
 766 over_op_modrdn( Operation *op, SlapReply *rs )
 767 {
 768         return over_op_func( op, rs, op_modrdn );
 769 }
 770
 771 static int
 772 over_op_add( Operation *op, SlapReply *rs )
 773 {
 774         return over_op_func( op, rs, op_add );
 775 }
 776
 777 static int
 778 over_op_delete( Operation *op, SlapReply *rs )
 779 {
 780         return over_op_func( op, rs, op_delete );
 781 }
 782
 783 static int
 784 over_op_abandon( Operation *op, SlapReply *rs )
 785 {
 786         return over_op_func( op, rs, op_abandon );
 787 }
 788
 789 static int
 790 over_op_cancel( Operation *op, SlapReply *rs )
 791 {
 792         return over_op_func( op, rs, op_cancel );
 793 }
 794
 795 static int
 796 over_op_extended( Operation *op, SlapReply *rs )
 797 {
 798         return over_op_func( op, rs, op_extended );
 799 }
 800
 801 static int
 802 over_aux_operational( Operation *op, SlapReply *rs )
 803 {
 804         return over_op_func( op, rs, op_aux_operational );
 805 }
 806
 807 static int
 808 over_aux_chk_referrals( Operation *op, SlapReply *rs )
 809 {
 810         return over_op_func( op, rs, op_aux_chk_referrals );
 811 }
 812
 813 static int
 814 over_aux_chk_controls( Operation *op, SlapReply *rs )
 815 {
 816         return over_op_func( op, rs, op_aux_chk_controls );
 817 }
 818
 819 enum conn_which {
 820         conn_init = 0,
 821         conn_destroy,
 822         conn_last
 823 };
 824
 825 static int
 826 over_connection_func(
 827         BackendDB       *bd,
 828         Connection      *conn,
 829         enum conn_which which
 830 )
 831 {
 832         slap_overinfo           *oi;
 833         slap_overinst           *on;
 834         BackendDB               db;
 835         int                     rc = SLAP_CB_CONTINUE;
 836         BI_connection_init      **func;
 837
 838         /* FIXME: used to happen for instance during abandon
 839          * when global overlays are used... */
 840         assert( bd != NULL );
 841
 842         oi = bd->bd_info->bi_private;
 843         on = oi->oi_list;
 844
 845         if ( !SLAP_ISOVERLAY( bd ) ) {
 846                 db = *bd;
 847                 db.be_flags |= SLAP_DBFLAG_OVERLAY;
 848                 bd = &db;
 849         }
 850
 851         for ( ; on; on = on->on_next ) {
 852                 func = &on->on_bi.bi_connection_init;
 853                 if ( func[ which ] ) {
 854                         bd->bd_info = (BackendInfo *)on;
 855                         rc = func[ which ]( bd, conn );
 856                         if ( rc != SLAP_CB_CONTINUE ) break;
 857                 }
 858         }
 859
 860         func = &oi->oi_orig->bi_connection_init;
 861         if ( func[ which ] && rc == SLAP_CB_CONTINUE ) {
 862                 bd->bd_info = oi->oi_orig;
 863                 rc = func[ which ]( bd, conn );
 864         }
 865         /* should not fall thru this far without anything happening... */
 866         if ( rc == SLAP_CB_CONTINUE ) {
 867                 rc = LDAP_UNWILLING_TO_PERFORM;
 868         }
 869
 870         return rc;
 871 }
 872
 873 static int
 874 over_connection_init(
 875         BackendDB       *bd,
 876         Connection      *conn
 877 )
 878 {
 879         return over_connection_func( bd, conn, conn_init );
 880 }
 881
 882 static int
 883 over_connection_destroy(
 884         BackendDB       *bd,
 885         Connection      *conn
 886 )
 887 {
 888         return over_connection_func( bd, conn, conn_destroy );
 889 }
 890
 891 int
 892 overlay_register(
 893         slap_overinst *on
 894 )
 895 {
 896         slap_overinst   *tmp;
 897
 898         /* FIXME: check for duplicates? */
 899         for ( tmp = overlays; tmp != NULL; tmp = tmp->on_next ) {
 900                 if ( strcmp( on->on_bi.bi_type, tmp->on_bi.bi_type ) == 0 ) {
 901                         Debug( LDAP_DEBUG_ANY,
 902                                 "overlay_register(\"%s\"): "
 903                                 "name already in use.\n",
 904                                 on->on_bi.bi_type, 0, 0 );
 905                         return -1;
 906                 }
 907
 908                 if ( on->on_bi.bi_obsolete_names != NULL ) {
 909                         int     i;
 910
 911                         for ( i = 0; on->on_bi.bi_obsolete_names[ i ] != NULL; i++ ) {
 912                                 if ( strcmp( on->on_bi.bi_obsolete_names[ i ], tmp->on_bi.bi_type ) == 0 ) {
 913                                         Debug( LDAP_DEBUG_ANY,
 914                                                 "overlay_register(\"%s\"): "
 915                                                 "obsolete name \"%s\" already in use "
 916                                                 "by overlay \"%s\".\n",
 917                                                 on->on_bi.bi_type,
 918                                                 on->on_bi.bi_obsolete_names[ i ],
 919                                                 tmp->on_bi.bi_type );
 920                                         return -1;
 921                                 }
 922                         }
 923                 }
 924
 925                 if ( tmp->on_bi.bi_obsolete_names != NULL ) {
 926                         int     i;
 927
 928                         for ( i = 0; tmp->on_bi.bi_obsolete_names[ i ] != NULL; i++ ) {
 929                                 int     j;
 930
 931                                 if ( strcmp( on->on_bi.bi_type, tmp->on_bi.bi_obsolete_names[ i ] ) == 0 ) {
 932                                         Debug( LDAP_DEBUG_ANY,
 933                                                 "overlay_register(\"%s\"): "
 934                                                 "name already in use "
 935                                                 "as obsolete by overlay \"%s\".\n",
 936                                                 on->on_bi.bi_type,
 937                                                 tmp->on_bi.bi_obsolete_names[ i ], 0 );
 938                                         return -1;
 939                                 }
 940
 941                                 if ( on->on_bi.bi_obsolete_names != NULL ) {
 942                                         for ( j = 0; on->on_bi.bi_obsolete_names[ j ] != NULL; j++ ) {
 943                                                 if ( strcmp( on->on_bi.bi_obsolete_names[ j ], tmp->on_bi.bi_obsolete_names[ i ] ) == 0 ) {
 944                                                         Debug( LDAP_DEBUG_ANY,
 945                                                                 "overlay_register(\"%s\"): "
 946                                                                 "obsolete name \"%s\" already in use "
 947                                                                 "as obsolete by overlay \"%s\".\n",
 948                                                                 on->on_bi.bi_type,
 949                                                                 on->on_bi.bi_obsolete_names[ j ],
 950                                                                 tmp->on_bi.bi_type );
 951                                                         return -1;
 952                                                 }
 953                                         }
 954                                 }
 955                         }
 956                 }
 957         }
 958
 959         on->on_next = overlays;
 960         overlays = on;
 961         return 0;
 962 }
 963
 964 /*
 965  * iterator on registered overlays; overlay_next( NULL ) returns the first
 966  * overlay; subsequent calls with the previously returned value allow to
 967  * iterate over the entire list; returns NULL when no more overlays are
 968  * registered.
 969  */
 970
 971 slap_overinst *
 972 overlay_next(
 973         slap_overinst *on
 974 )
 975 {
 976         if ( on == NULL ) {
 977                 return overlays;
 978         }
 979
 980         return on->on_next;
 981 }
 982
 983 /*
 984  * returns a specific registered overlay based on the type; NULL if not
 985  * registered.
 986  */
 987
 988 slap_overinst *
 989 overlay_find( const char *over_type )
 990 {
 991         slap_overinst *on = overlays;
 992
 993         assert( over_type != NULL );
 994
 995         for ( ; on; on = on->on_next ) {
 996                 if ( strcmp( on->on_bi.bi_type, over_type ) == 0 ) {
 997                         goto foundit;
 998                 }
 999
1000                 if ( on->on_bi.bi_obsolete_names != NULL ) {
1001                         int     i;
1002
1003                         for ( i = 0; on->on_bi.bi_obsolete_names[ i ] != NULL; i++ ) {
1004                                 if ( strcmp( on->on_bi.bi_obsolete_names[ i ], over_type ) == 0 ) {
1005                                         Debug( LDAP_DEBUG_ANY,
1006                                                 "overlay_find(\"%s\"): "
1007                                                 "obsolete name for \"%s\".\n",
1008                                                 on->on_bi.bi_obsolete_names[ i ],
1009                                                 on->on_bi.bi_type, 0 );
1010                                         goto foundit;
1011                                 }
1012                         }
1013                 }
1014         }
1015
1016 foundit:;
1017         return on;
1018 }
1019
1020 static const char overtype[] = "over";
1021
1022 /*
1023  * returns TRUE (1) if the database is actually an overlay instance;
1024  * FALSE (0) otherwise.
1025  */
1026
1027 int
1028 overlay_is_over( BackendDB *be )
1029 {
1030         return be->bd_info->bi_type == overtype;
1031 }
1032
1033 /*
1034  * returns TRUE (1) if the given database is actually an overlay
1035  * instance and, somewhere in the list, contains the requested overlay;
1036  * FALSE (0) otherwise.
1037  */
1038
1039 int
1040 overlay_is_inst( BackendDB *be, const char *over_type )
1041 {
1042         slap_overinst   *on;
1043
1044         assert( be != NULL );
1045
1046         if ( !overlay_is_over( be ) ) {
1047                 return 0;
1048         }
1049
1050         on = ((slap_overinfo *)be->bd_info->bi_private)->oi_list;
1051         for ( ; on; on = on->on_next ) {
1052                 if ( strcmp( on->on_bi.bi_type, over_type ) == 0 ) {
1053                         return 1;
1054                 }
1055         }
1056
1057         return 0;
1058 }
1059
1060 int
1061 overlay_register_control( BackendDB *be, const char *oid )
1062 {
1063         int             gotit = 0;
1064         int             cid;
1065
1066         if ( slap_find_control_id( oid, &cid ) == LDAP_CONTROL_NOT_FOUND ) {
1067                 return -1;
1068         }
1069
1070         if ( SLAP_ISGLOBALOVERLAY( be ) ) {
1071                 BackendDB *bd;
1072
1073                 /* add to all backends... */
1074                 LDAP_STAILQ_FOREACH( bd, &backendDB, be_next ) {
1075                         if ( bd == be->bd_self ) {
1076                                 gotit = 1;
1077                         }
1078
1079                         /* overlays can be instanciated multiple times, use
1080                          * be_ctrls[ cid ] as an instance counter, so that the
1081                          * overlay's controls are only really disabled after the
1082                          * last instance called overlay_register_control() */
1083                         bd->be_ctrls[ cid ]++;
1084                         bd->be_ctrls[ SLAP_MAX_CIDS ] = 1;
1085                 }
1086
1087         }
1088
1089         if ( !gotit ) {
1090                 /* overlays can be instanciated multiple times, use
1091                  * be_ctrls[ cid ] as an instance counter, so that the
1092                  * overlay's controls are only really unregistered after the
1093                  * last instance called overlay_register_control() */
1094                 be->bd_self->be_ctrls[ cid ]++;
1095                 be->bd_self->be_ctrls[ SLAP_MAX_CIDS ] = 1;
1096         }
1097
1098         return 0;
1099 }
1100
1101 #ifdef SLAP_CONFIG_DELETE
1102 void
1103 overlay_unregister_control( BackendDB *be, const char *oid )
1104 {
1105         int             gotit = 0;
1106         int             cid;
1107
1108         if ( slap_find_control_id( oid, &cid ) == LDAP_CONTROL_NOT_FOUND ) {
1109                 return;
1110         }
1111
1112         if ( SLAP_ISGLOBALOVERLAY( be ) ) {
1113                 BackendDB *bd;
1114
1115                 /* remove from all backends... */
1116                 LDAP_STAILQ_FOREACH( bd, &backendDB, be_next ) {
1117                         if ( bd == be->bd_self ) {
1118                                 gotit = 1;
1119                         }
1120
1121                         bd->be_ctrls[ cid ]--;
1122                 }
1123         }
1124
1125         if ( !gotit ) {
1126                 be->bd_self->be_ctrls[ cid ]--;
1127         }
1128 }
1129 #endif /* SLAP_CONFIG_DELETE */
1130
1131 void
1132 overlay_destroy_one( BackendDB *be, slap_overinst *on )
1133 {
1134         slap_overinfo *oi = on->on_info;
1135         slap_overinst **oidx;
1136
1137         for ( oidx = &oi->oi_list; *oidx; oidx = &(*oidx)->on_next ) {
1138                 if ( *oidx == on ) {
1139                         *oidx = on->on_next;
1140                         if ( on->on_bi.bi_db_destroy ) {
1141                                 BackendInfo *bi_orig = be->bd_info;
1142                                 be->bd_info = (BackendInfo *)on;
1143                                 on->on_bi.bi_db_destroy( be, NULL );
1144                                 be->bd_info = bi_orig;
1145                         }
1146                         free( on );
1147                         break;
1148                 }
1149         }
1150 }
1151
1152 #ifdef SLAP_CONFIG_DELETE
1153 typedef struct ov_remove_ctx {
1154         BackendDB *be;
1155         slap_overinst *on;
1156 } ov_remove_ctx;
1157
1158 int
1159 overlay_remove_cb( Operation *op, SlapReply *rs )
1160 {
1161         ov_remove_ctx *rm_ctx = (ov_remove_ctx*) op->o_callback->sc_private;
1162         BackendInfo *bi_orig = rm_ctx->be->bd_info;
1163
1164         rm_ctx->be->bd_info = (BackendInfo*) rm_ctx->on;
1165
1166         if ( rm_ctx->on->on_bi.bi_db_close ) {
1167                 rm_ctx->on->on_bi.bi_db_close( rm_ctx->be, NULL );
1168         }
1169         if ( rm_ctx->on->on_bi.bi_db_destroy ) {
1170                 rm_ctx->on->on_bi.bi_db_destroy( rm_ctx->be, NULL );
1171         }
1172
1173         /* clean up after removing last overlay */
1174         if ( ! rm_ctx->on->on_info->oi_list ) {
1175                 /* reset db flags and bd_info to orig */
1176                 SLAP_DBFLAGS( rm_ctx->be ) &= ~SLAP_DBFLAG_GLOBAL_OVERLAY;
1177                 rm_ctx->be->bd_info = rm_ctx->on->on_info->oi_orig;
1178                 ch_free(rm_ctx->on->on_info);
1179         } else {
1180                 rm_ctx->be->bd_info = bi_orig;
1181         }
1182         free( rm_ctx->on );
1183         op->o_tmpfree(rm_ctx, op->o_tmpmemctx);
1184         return SLAP_CB_CONTINUE;
1185 }
1186
1187 void
1188 overlay_remove( BackendDB *be, slap_overinst *on, Operation *op )
1189 {
1190         slap_overinfo *oi = on->on_info;
1191         slap_overinst **oidx;
1192         ov_remove_ctx *rm_ctx;
1193         slap_callback *rm_cb, *cb;
1194
1195         /* remove overlay from oi_list */
1196         for ( oidx = &oi->oi_list; *oidx; oidx = &(*oidx)->on_next ) {
1197                 if ( *oidx == on ) {
1198                         *oidx = on->on_next;
1199                         break;
1200                 }
1201         }
1202
1203         /* The db_close and db_destroy handlers to cleanup a release
1204          * the overlay's resources are called from the cleanup callback
1205          */
1206         rm_ctx = op->o_tmpalloc( sizeof( ov_remove_ctx ), op->o_tmpmemctx );
1207         rm_ctx->be = be;
1208         rm_ctx->on = on;
1209
1210         rm_cb = op->o_tmpalloc( sizeof( slap_callback ), op->o_tmpmemctx );
1211         rm_cb->sc_next = NULL;
1212         rm_cb->sc_cleanup = overlay_remove_cb;
1213         rm_cb->sc_response = NULL;
1214         rm_cb->sc_private = (void*) rm_ctx;
1215
1216         /* Append callback to the end of the list */
1217         if ( !op->o_callback ) {
1218                 op->o_callback = rm_cb;
1219         } else {
1220                 for ( cb = op->o_callback; cb->sc_next; cb = cb->sc_next );
1221                 cb->sc_next = rm_cb;
1222         }
1223 }
1224 #endif /* SLAP_CONFIG_DELETE */
1225
1226 void
1227 overlay_insert( BackendDB *be, slap_overinst *on2, slap_overinst ***prev,
1228         int idx )
1229 {
1230         slap_overinfo *oi = (slap_overinfo *)be->bd_info;
1231
1232         if ( idx == -1 ) {
1233                 on2->on_next = oi->oi_list;
1234                 oi->oi_list = on2;
1235         } else {
1236                 int i, novs;
1237                 slap_overinst *on, **prev;
1238
1239                 /* Since the list is in reverse order and is singly linked,
1240                  * we have to count the overlays and then insert backwards.
1241                  * Adding on overlay at a specific point should be a pretty
1242                  * infrequent occurrence.
1243                  */
1244                 novs = 0;
1245                 for ( on = oi->oi_list; on; on=on->on_next )
1246                         novs++;
1247
1248                 if (idx > novs)
1249                         idx = 0;
1250                 else
1251                         idx = novs - idx;
1252
1253                 /* advance to insertion point */
1254                 prev = &oi->oi_list;
1255                 for ( i=0; i<idx; i++ ) {
1256                         on = *prev;
1257                         prev = &on->on_next;
1258                 }
1259                 /* insert */
1260                 on2->on_next = *prev;
1261                 *prev = on2;
1262         }
1263 }
1264
1265 void
1266 overlay_move( BackendDB *be, slap_overinst *on, int idx )
1267 {
1268         slap_overinfo *oi = (slap_overinfo *)be->bd_info;
1269         slap_overinst **onp;
1270
1271         for (onp = &oi->oi_list; *onp; onp= &(*onp)->on_next) {
1272                 if ( *onp == on ) {
1273                         *onp = on->on_next;
1274                         break;
1275                 }
1276         }
1277         overlay_insert( be, on, &onp, idx );
1278 }
1279
1280 /* add an overlay to a particular backend. */
1281 int
1282 overlay_config( BackendDB *be, const char *ov, int idx, BackendInfo **res, ConfigReply *cr )
1283 {
1284         slap_overinst *on = NULL, *on2 = NULL, **prev;
1285         slap_overinfo *oi = NULL;
1286         BackendInfo *bi = NULL;
1287
1288         if ( res )
1289                 *res = NULL;
1290
1291         on = overlay_find( ov );
1292         if ( !on ) {
1293                 Debug( LDAP_DEBUG_ANY, "overlay \"%s\" not found\n", ov, 0, 0 );
1294                 return 1;
1295         }
1296
1297         /* If this is the first overlay on this backend, set up the
1298          * overlay info structure
1299          */
1300         if ( !overlay_is_over( be ) ) {
1301                 int     isglobal = 0;
1302
1303                 /* NOTE: the first time a global overlay is configured,
1304                  * frontendDB gets this flag; it is used later by overlays
1305                  * to determine if they're stacked on top of the frontendDB */
1306                 if ( be->bd_info == frontendDB->bd_info || SLAP_ISGLOBALOVERLAY( be ) ) {
1307                         isglobal = 1;
1308                         if ( on->on_bi.bi_flags & SLAPO_BFLAG_DBONLY ) {
1309                                 Debug( LDAP_DEBUG_ANY, "overlay_config(): "
1310                                         "overlay \"%s\" cannot be global.\n",
1311                                         ov, 0, 0 );
1312                                 return 1;
1313                         }
1314
1315                 } else if ( on->on_bi.bi_flags & SLAPO_BFLAG_GLOBONLY ) {
1316                         Debug( LDAP_DEBUG_ANY, "overlay_config(): "
1317                                 "overlay \"%s\" can only be global.\n",
1318                                 ov, 0, 0 );
1319                         return 1;
1320                 }
1321
1322                 oi = ch_malloc( sizeof( slap_overinfo ) );
1323                 oi->oi_orig = be->bd_info;
1324                 oi->oi_bi = *be->bd_info;
1325                 oi->oi_origdb = be;
1326
1327                 if ( isglobal ) {
1328                         SLAP_DBFLAGS( be ) |= SLAP_DBFLAG_GLOBAL_OVERLAY;
1329                 }
1330
1331                 /* Save a pointer to ourself in bi_private.
1332                  */
1333                 oi->oi_bi.bi_private = oi;
1334                 oi->oi_list = NULL;
1335                 bi = (BackendInfo *)oi;
1336
1337                 bi->bi_type = (char *)overtype;
1338
1339                 bi->bi_db_config = over_db_config;
1340                 bi->bi_db_open = over_db_open;
1341                 bi->bi_db_close = over_db_close;
1342                 bi->bi_db_destroy = over_db_destroy;
1343
1344                 bi->bi_op_bind = over_op_bind;
1345                 bi->bi_op_unbind = over_op_unbind;
1346                 bi->bi_op_search = over_op_search;
1347                 bi->bi_op_compare = over_op_compare;
1348                 bi->bi_op_modify = over_op_modify;
1349                 bi->bi_op_modrdn = over_op_modrdn;
1350                 bi->bi_op_add = over_op_add;
1351                 bi->bi_op_delete = over_op_delete;
1352                 bi->bi_op_abandon = over_op_abandon;
1353                 bi->bi_op_cancel = over_op_cancel;
1354
1355                 bi->bi_extended = over_op_extended;
1356
1357                 /*
1358                  * this is fine because it has the same
1359                  * args of the operations; we need to rework
1360                  * all the hooks to share the same args
1361                  * of the operations...
1362                  */
1363                 bi->bi_operational = over_aux_operational;
1364                 bi->bi_chk_referrals = over_aux_chk_referrals;
1365                 bi->bi_chk_controls = over_aux_chk_controls;
1366
1367                 /* these have specific arglists */
1368                 bi->bi_entry_get_rw = over_entry_get_rw;
1369                 bi->bi_entry_release_rw = over_entry_release_rw;
1370                 bi->bi_access_allowed = over_access_allowed;
1371                 bi->bi_acl_group = over_acl_group;
1372                 bi->bi_acl_attribute = over_acl_attribute;
1373
1374                 bi->bi_connection_init = over_connection_init;
1375                 bi->bi_connection_destroy = over_connection_destroy;
1376
1377                 be->bd_info = bi;
1378
1379         } else {
1380                 if ( overlay_is_inst( be, ov ) ) {
1381                         if ( SLAPO_SINGLE( be ) ) {
1382                                 Debug( LDAP_DEBUG_ANY, "overlay_config(): "
1383                                         "overlay \"%s\" already in list\n",
1384                                         ov, 0, 0 );
1385                                 return 1;
1386                         }
1387                 }
1388
1389                 oi = be->bd_info->bi_private;
1390         }
1391
1392         /* Insert new overlay into list. By default overlays are
1393          * added to head of list and executed in LIFO order.
1394          */
1395         on2 = ch_calloc( 1, sizeof(slap_overinst) );
1396         *on2 = *on;
1397         on2->on_info = oi;
1398
1399         prev = &oi->oi_list;
1400         /* Do we need to find the insertion point? */
1401         if ( idx >= 0 ) {
1402                 int i;
1403
1404                 /* count current overlays */
1405                 for ( i=0, on=oi->oi_list; on; on=on->on_next, i++ );
1406
1407                 /* are we just appending a new one? */
1408                 if ( idx >= i )
1409                         idx = -1;
1410         }
1411         overlay_insert( be, on2, &prev, idx );
1412
1413         /* Any initialization needed? */
1414         if ( on2->on_bi.bi_db_init ) {
1415                 int rc;
1416                 be->bd_info = (BackendInfo *)on2;
1417                 rc = on2->on_bi.bi_db_init( be, cr);
1418                 be->bd_info = (BackendInfo *)oi;
1419                 if ( rc ) {
1420                         *prev = on2->on_next;
1421                         ch_free( on2 );
1422                         on2 = NULL;
1423                         return rc;
1424                 }
1425         }
1426
1427         if ( res )
1428                 *res = &on2->on_bi;
1429
1430         return 0;
1431 }
1432