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 2003-2017 The OpenLDAP Foundation.
   6  * All rights reserved.
   7  *
   8  * Redistribution and use in source and binary forms, with or without
   9  * modification, are permitted only as authorized by the OpenLDAP
  10  * Public License.
  11  *
  12  * A copy of this license is available in the file LICENSE in the
  13  * top-level directory of the distribution or, alternatively, at
  14  * <http://www.OpenLDAP.org/license.html>.
  15  */
  16
  17 /* Functions to overlay other modules over a backend. */
  18
  19 #include "portable.h"
  20
  21 #include <stdio.h>
  22
  23 #include <ac/string.h>
  24 #include <ac/socket.h>
  25
  26 #define SLAPD_TOOLS
  27 #include "slap.h"
  28 #include "config.h"
  29
  30 static slap_overinst *overlays;
  31
  32 static int
  33 over_db_config(
  34         BackendDB *be,
  35         const char *fname,
  36         int lineno,
  37         int argc,
  38         char **argv
  39 )
  40 {
  41         slap_overinfo *oi = be->bd_info->bi_private;
  42         slap_overinst *on = oi->oi_list;
  43         BackendInfo *bi_orig = be->bd_info;
  44         struct ConfigOCs *be_cf_ocs = be->be_cf_ocs;
  45         ConfigArgs ca = {0};
  46         int rc = 0;
  47
  48         if ( oi->oi_orig->bi_db_config ) {
  49                 be->bd_info = oi->oi_orig;
  50                 be->be_cf_ocs = oi->oi_orig->bi_cf_ocs;
  51                 rc = oi->oi_orig->bi_db_config( be, fname, lineno,
  52                         argc, argv );
  53
  54                 if ( be->bd_info != oi->oi_orig ) {
  55                         slap_overinfo   *oi2;
  56                         slap_overinst   *on2, **onp;
  57                         BackendDB       be2 = *be;
  58                         int             i;
  59
  60                         /* a database added an overlay;
  61                          * work it around... */
  62                         assert( overlay_is_over( be ) );
  63
  64                         oi2 = ( slap_overinfo * )be->bd_info->bi_private;
  65                         on2 = oi2->oi_list;
  66
  67                         /* need to put a uniqueness check here as well;
  68                          * note that in principle there could be more than
  69                          * one overlay as a result of multiple calls to
  70                          * overlay_config() */
  71                         be2.bd_info = (BackendInfo *)oi;
  72
  73                         for ( i = 0, onp = &on2; *onp; i++, onp = &(*onp)->on_next ) {
  74                                 if ( overlay_is_inst( &be2, (*onp)->on_bi.bi_type ) ) {
  75                                         Debug( LDAP_DEBUG_ANY, "over_db_config(): "
  76                                                         "warning, freshly added "
  77                                                         "overlay #%d \"%s\" is already in list\n",
  78                                                         i, (*onp)->on_bi.bi_type, 0 );
  79
  80                                         /* NOTE: if the overlay already exists,
  81                                          * there is no way to merge the results
  82                                          * of the configuration that may have
  83                                          * occurred during bi_db_config(); we
  84                                          * just issue a warning, and the
  85                                          * administrator should deal with this */
  86                                 }
  87                         }
  88                         *onp = oi->oi_list;
  89
  90                         oi->oi_list = on2;
  91
  92                         ch_free( be->bd_info );
  93                 }
  94
  95                 be->bd_info = (BackendInfo *)oi;
  96                 if ( rc != SLAP_CONF_UNKNOWN ) return rc;
  97         }
  98
  99         ca.argv = argv;
 100         ca.argc = argc;
 101         ca.fname = fname;
 102         ca.lineno = lineno;
 103         ca.be = be;
 104         snprintf( ca.log, sizeof( ca.log ), "%s: line %d",
 105                         ca.fname, ca.lineno );
 106         ca.op = SLAP_CONFIG_ADD;
 107         ca.valx = -1;
 108
 109         for (; on; on=on->on_next) {
 110                 rc = SLAP_CONF_UNKNOWN;
 111                 if (on->on_bi.bi_cf_ocs) {
 112                         ConfigTable *ct;
 113                         ca.bi = &on->on_bi;
 114                         ct = config_find_keyword( on->on_bi.bi_cf_ocs->co_table, &ca );
 115                         if ( ct ) {
 116                                 ca.table = on->on_bi.bi_cf_ocs->co_type;
 117                                 rc = config_add_vals( ct, &ca );
 118                                 if ( rc != SLAP_CONF_UNKNOWN )
 119                                         break;
 120                         }
 121                 }
 122                 if (on->on_bi.bi_db_config && rc == SLAP_CONF_UNKNOWN) {
 123                         be->bd_info = &on->on_bi;
 124                         rc = on->on_bi.bi_db_config( be, fname, lineno,
 125                                 argc, argv );
 126                         if ( rc != SLAP_CONF_UNKNOWN ) break;
 127                 }
 128         }
 129         be->bd_info = bi_orig;
 130         be->be_cf_ocs = be_cf_ocs;
 131
 132         return rc;
 133 }
 134
 135 static int
 136 over_db_open(
 137         BackendDB *be,
 138         ConfigReply *cr
 139 )
 140 {
 141         slap_overinfo *oi = be->bd_info->bi_private;
 142         slap_overinst *on = oi->oi_list;
 143         BackendDB db = *be;
 144         int rc = 0;
 145
 146         db.be_flags |= SLAP_DBFLAG_OVERLAY;
 147         db.bd_info = oi->oi_orig;
 148         if ( db.bd_info->bi_db_open ) {
 149                 rc = db.bd_info->bi_db_open( &db, cr );
 150         }
 151
 152         for (; on && rc == 0; on=on->on_next) {
 153                 if ( on->on_bi.bi_flags & SLAPO_BFLAG_DISABLED )
 154                         continue;
 155                 db.bd_info = &on->on_bi;
 156                 if ( db.bd_info->bi_db_open ) {
 157                         rc = db.bd_info->bi_db_open( &db, cr );
 158                 }
 159         }
 160
 161         return rc;
 162 }
 163
 164 static int
 165 over_db_close(
 166         BackendDB *be,
 167         ConfigReply *cr
 168 )
 169 {
 170         slap_overinfo *oi = be->bd_info->bi_private;
 171         slap_overinst *on = oi->oi_list;
 172         BackendInfo *bi_orig = be->bd_info;
 173         int rc = 0;
 174
 175         for (; on && rc == 0; on=on->on_next) {
 176                 if ( on->on_bi.bi_flags & SLAPO_BFLAG_DISABLED )
 177                         continue;
 178                 be->bd_info = &on->on_bi;
 179                 if ( be->bd_info->bi_db_close ) {
 180                         rc = be->bd_info->bi_db_close( be, cr );
 181                 }
 182         }
 183
 184         if ( oi->oi_orig->bi_db_close ) {
 185                 be->bd_info = oi->oi_orig;
 186                 rc = be->bd_info->bi_db_close( be, cr );
 187         }
 188
 189         be->bd_info = bi_orig;
 190         return rc;
 191 }
 192
 193 static int
 194 over_db_destroy(
 195         BackendDB *be,
 196         ConfigReply *cr
 197 )
 198 {
 199         slap_overinfo *oi = be->bd_info->bi_private;
 200         slap_overinst *on = oi->oi_list, *next;
 201         BackendInfo *bi_orig = be->bd_info;
 202         int rc = 0;
 203
 204         be->bd_info = oi->oi_orig;
 205         if ( be->bd_info->bi_db_destroy ) {
 206                 rc = be->bd_info->bi_db_destroy( be, cr );
 207         }
 208
 209         for (; on && rc == 0; on=on->on_next) {
 210                 if ( on->on_bi.bi_flags & SLAPO_BFLAG_DISABLED )
 211                         continue;
 212                 be->bd_info = &on->on_bi;
 213                 if ( be->bd_info->bi_db_destroy ) {
 214                         rc = be->bd_info->bi_db_destroy( be, cr );
 215                 }
 216         }
 217
 218         on = oi->oi_list;
 219         if ( on ) {
 220                 for (next = on->on_next; on; on=next) {
 221                         next = on->on_next;
 222                         free( on );
 223                 }
 224         }
 225         be->bd_info = bi_orig;
 226         free( oi );
 227         return rc;
 228 }
 229
 230 static int
 231 over_back_response ( Operation *op, SlapReply *rs )
 232 {
 233         slap_overinfo *oi = op->o_callback->sc_private;
 234         slap_overinst *on = oi->oi_list;
 235         int rc = SLAP_CB_CONTINUE;
 236         BackendDB *be = op->o_bd, db = *op->o_bd;
 237
 238         db.be_flags |= SLAP_DBFLAG_OVERLAY;
 239         op->o_bd = &db;
 240         for (; on; on=on->on_next ) {
 241                 if ( on->on_bi.bi_flags & SLAPO_BFLAG_DISABLED )
 242                         continue;
 243                 if ( on->on_response ) {
 244                         db.bd_info = (BackendInfo *)on;
 245                         rc = on->on_response( op, rs );
 246                         if ( rc != SLAP_CB_CONTINUE ) break;
 247                 }
 248         }
 249         /* Bypass the remaining on_response layers, but allow
 250          * normal execution to continue.
 251          */
 252         if ( rc == SLAP_CB_BYPASS )
 253                 rc = SLAP_CB_CONTINUE;
 254         op->o_bd = be;
 255         return rc;
 256 }
 257
 258 static int
 259 over_access_allowed(
 260         Operation               *op,
 261         Entry                   *e,
 262         AttributeDescription    *desc,
 263         struct berval           *val,
 264         slap_access_t           access,
 265         AccessControlState      *state,
 266         slap_mask_t             *maskp )
 267 {
 268         slap_overinfo *oi;
 269         slap_overinst *on;
 270         BackendInfo *bi;
 271         BackendDB *be = op->o_bd, db;
 272         int rc = SLAP_CB_CONTINUE;
 273
 274         /* FIXME: used to happen for instance during abandon
 275          * when global overlays are used... */
 276         assert( op->o_bd != NULL );
 277
 278         bi = op->o_bd->bd_info;
 279         /* Were we invoked on the frontend? */
 280         if ( !bi->bi_access_allowed ) {
 281                 oi = frontendDB->bd_info->bi_private;
 282         } else {
 283                 oi = op->o_bd->bd_info->bi_private;
 284         }
 285         on = oi->oi_list;
 286
 287         for ( ; on; on = on->on_next ) {
 288                 if ( on->on_bi.bi_flags & SLAPO_BFLAG_DISABLED )
 289                         continue;
 290                 if ( on->on_bi.bi_access_allowed ) {
 291                         /* NOTE: do not copy the structure until required */
 292                         if ( !SLAP_ISOVERLAY( op->o_bd ) ) {
 293                                 db = *op->o_bd;
 294                                 db.be_flags |= SLAP_DBFLAG_OVERLAY;
 295                                 op->o_bd = &db;
 296                         }
 297
 298                         op->o_bd->bd_info = (BackendInfo *)on;
 299                         rc = on->on_bi.bi_access_allowed( op, e,
 300                                 desc, val, access, state, maskp );
 301                         if ( rc != SLAP_CB_CONTINUE ) break;
 302                 }
 303         }
 304
 305         if ( rc == SLAP_CB_CONTINUE ) {
 306                 BI_access_allowed       *bi_access_allowed;
 307
 308                 /* if the database structure was changed, o_bd points to a
 309                  * copy of the structure; put the original bd_info in place */
 310                 if ( SLAP_ISOVERLAY( op->o_bd ) ) {
 311                         op->o_bd->bd_info = oi->oi_orig;
 312                 }
 313
 314                 if ( oi->oi_orig->bi_access_allowed ) {
 315                         bi_access_allowed = oi->oi_orig->bi_access_allowed;
 316                 } else {
 317                         bi_access_allowed = slap_access_allowed;
 318                 }
 319
 320                 rc = bi_access_allowed( op, e,
 321                         desc, val, access, state, maskp );
 322         }
 323         /* should not fall thru this far without anything happening... */
 324         if ( rc == SLAP_CB_CONTINUE ) {
 325                 /* access not allowed */
 326                 rc = 0;
 327         }
 328
 329         op->o_bd = be;
 330         if ( SLAP_ISOVERLAY( op->o_bd ) ) {
 331                 op->o_bd->bd_info = bi;
 332         }
 333
 334         return rc;
 335 }
 336
 337 int
 338 overlay_entry_get_ov(
 339         Operation               *op,
 340         struct berval   *dn,
 341         ObjectClass             *oc,
 342         AttributeDescription    *ad,
 343         int     rw,
 344         Entry   **e,
 345         slap_overinst *on )
 346 {
 347         slap_overinfo *oi = on->on_info;
 348         BackendDB *be = op->o_bd, db;
 349         BackendInfo *bi = op->o_bd->bd_info;
 350         int rc = SLAP_CB_CONTINUE;
 351
 352         for ( ; on; on = on->on_next ) {
 353                 if ( on->on_bi.bi_flags & SLAPO_BFLAG_DISABLED )
 354                         continue;
 355                 if ( on->on_bi.bi_entry_get_rw ) {
 356                         /* NOTE: do not copy the structure until required */
 357                         if ( !SLAP_ISOVERLAY( op->o_bd ) ) {
 358                                 db = *op->o_bd;
 359                                 db.be_flags |= SLAP_DBFLAG_OVERLAY;
 360                                 op->o_bd = &db;
 361                         }
 362
 363                         op->o_bd->bd_info = (BackendInfo *)on;
 364                         rc = on->on_bi.bi_entry_get_rw( op, dn,
 365                                 oc, ad, rw, e );
 366                         if ( rc != SLAP_CB_CONTINUE ) break;
 367                 }
 368         }
 369
 370         if ( rc == SLAP_CB_CONTINUE ) {
 371                 /* if the database structure was changed, o_bd points to a
 372                  * copy of the structure; put the original bd_info in place */
 373                 if ( SLAP_ISOVERLAY( op->o_bd ) ) {
 374                         op->o_bd->bd_info = oi->oi_orig;
 375                 }
 376
 377                 if ( oi->oi_orig->bi_entry_get_rw ) {
 378                         rc = oi->oi_orig->bi_entry_get_rw( op, dn,
 379                                 oc, ad, rw, e );
 380                 }
 381         }
 382         /* should not fall thru this far without anything happening... */
 383         if ( rc == SLAP_CB_CONTINUE ) {
 384                 rc = LDAP_UNWILLING_TO_PERFORM;
 385         }
 386
 387         op->o_bd = be;
 388         if ( SLAP_ISOVERLAY( op->o_bd ) ) {
 389                 op->o_bd->bd_info = bi;
 390         }
 391
 392         return rc;
 393 }
 394
 395 static int
 396 over_entry_get_rw(
 397         Operation               *op,
 398         struct berval   *dn,
 399         ObjectClass             *oc,
 400         AttributeDescription    *ad,
 401         int     rw,
 402         Entry   **e )
 403 {
 404         slap_overinfo *oi;
 405         slap_overinst *on;
 406
 407         assert( op->o_bd != NULL );
 408
 409         oi = op->o_bd->bd_info->bi_private;
 410         on = oi->oi_list;
 411
 412         return overlay_entry_get_ov( op, dn, oc, ad, rw, e, on );
 413 }
 414
 415 int
 416 overlay_entry_release_ov(
 417         Operation       *op,
 418         Entry   *e,
 419         int rw,
 420         slap_overinst *on )
 421 {
 422         slap_overinfo *oi = on->on_info;
 423         BackendDB *be = op->o_bd, db;
 424         BackendInfo *bi = op->o_bd->bd_info;
 425         int rc = SLAP_CB_CONTINUE;
 426
 427         for ( ; on; on = on->on_next ) {
 428                 if ( on->on_bi.bi_flags & SLAPO_BFLAG_DISABLED )
 429                         continue;
 430                 if ( on->on_bi.bi_entry_release_rw ) {
 431                         /* NOTE: do not copy the structure until required */
 432                         if ( !SLAP_ISOVERLAY( op->o_bd ) ) {
 433                                 db = *op->o_bd;
 434                                 db.be_flags |= SLAP_DBFLAG_OVERLAY;
 435                                 op->o_bd = &db;
 436                         }
 437
 438                         op->o_bd->bd_info = (BackendInfo *)on;
 439                         rc = on->on_bi.bi_entry_release_rw( op, e, rw );
 440                         if ( rc != SLAP_CB_CONTINUE ) break;
 441                 }
 442         }
 443
 444         if ( rc == SLAP_CB_CONTINUE ) {
 445                 /* if the database structure was changed, o_bd points to a
 446                  * copy of the structure; put the original bd_info in place */
 447                 if ( SLAP_ISOVERLAY( op->o_bd ) ) {
 448                         op->o_bd->bd_info = oi->oi_orig;
 449                 }
 450
 451                 if ( oi->oi_orig->bi_entry_release_rw ) {
 452                         rc = oi->oi_orig->bi_entry_release_rw( op, e, rw );
 453                 }
 454         }
 455         /* should not fall thru this far without anything happening... */
 456         if ( rc == SLAP_CB_CONTINUE ) {
 457                 entry_free( e );
 458                 rc = 0;
 459         }
 460
 461         op->o_bd = be;
 462         if ( SLAP_ISOVERLAY( op->o_bd ) ) {
 463                 op->o_bd->bd_info = bi;
 464         }
 465
 466         return rc;
 467 }
 468
 469 static int
 470 over_entry_release_rw(
 471         Operation       *op,
 472         Entry   *e,
 473         int rw )
 474 {
 475         slap_overinfo *oi;
 476         slap_overinst *on;
 477
 478         assert( op->o_bd != NULL );
 479
 480         oi = op->o_bd->bd_info->bi_private;
 481         on = oi->oi_list;
 482
 483         return overlay_entry_release_ov( op, e, rw, on );
 484 }
 485
 486 static int
 487 over_acl_group(
 488         Operation               *op,
 489         Entry                   *e,
 490         struct berval           *gr_ndn,
 491         struct berval           *op_ndn,
 492         ObjectClass             *group_oc,
 493         AttributeDescription    *group_at )
 494 {
 495         slap_overinfo *oi;
 496         slap_overinst *on;
 497         BackendInfo *bi;
 498         BackendDB *be = op->o_bd, db;
 499         int rc = SLAP_CB_CONTINUE;
 500
 501         /* FIXME: used to happen for instance during abandon
 502          * when global overlays are used... */
 503         assert( be != NULL );
 504
 505         bi = be->bd_info;
 506         oi = bi->bi_private;
 507         on = oi->oi_list;
 508
 509         for ( ; on; on = on->on_next ) {
 510                 if ( on->on_bi.bi_flags & SLAPO_BFLAG_DISABLED )
 511                         continue;
 512                 if ( on->on_bi.bi_acl_group ) {
 513                         /* NOTE: do not copy the structure until required */
 514                         if ( !SLAP_ISOVERLAY( op->o_bd ) ) {
 515                                 db = *op->o_bd;
 516                                 db.be_flags |= SLAP_DBFLAG_OVERLAY;
 517                                 op->o_bd = &db;
 518                         }
 519
 520                         op->o_bd->bd_info = (BackendInfo *)on;
 521                         rc = on->on_bi.bi_acl_group( op, e,
 522                                 gr_ndn, op_ndn, group_oc, group_at );
 523                         if ( rc != SLAP_CB_CONTINUE ) break;
 524                 }
 525         }
 526
 527         if ( rc == SLAP_CB_CONTINUE ) {
 528                 BI_acl_group            *bi_acl_group;
 529
 530                 /* if the database structure was changed, o_bd points to a
 531                  * copy of the structure; put the original bd_info in place */
 532                 if ( SLAP_ISOVERLAY( op->o_bd ) ) {
 533                         op->o_bd->bd_info = oi->oi_orig;
 534                 }
 535
 536                 if ( oi->oi_orig->bi_acl_group ) {
 537                         bi_acl_group = oi->oi_orig->bi_acl_group;
 538                 } else {
 539                         bi_acl_group = backend_group;
 540                 }
 541
 542                 rc = bi_acl_group( op, e,
 543                         gr_ndn, op_ndn, group_oc, group_at );
 544         }
 545         /* should not fall thru this far without anything happening... */
 546         if ( rc == SLAP_CB_CONTINUE ) {
 547                 /* access not allowed */
 548                 rc = 0;
 549         }
 550
 551         op->o_bd = be;
 552         if ( SLAP_ISOVERLAY( op->o_bd ) ) {
 553                 op->o_bd->bd_info = bi;
 554         }
 555
 556         return rc;
 557 }
 558
 559 static int
 560 over_acl_attribute(
 561         Operation               *op,
 562         Entry                   *target,
 563         struct berval           *entry_ndn,
 564         AttributeDescription    *entry_at,
 565         BerVarray               *vals,
 566         slap_access_t           access )
 567 {
 568         slap_overinfo *oi;
 569         slap_overinst *on;
 570         BackendInfo *bi;
 571         BackendDB *be = op->o_bd, db;
 572         int rc = SLAP_CB_CONTINUE;
 573
 574         /* FIXME: used to happen for instance during abandon
 575          * when global overlays are used... */
 576         assert( be != NULL );
 577
 578         bi = be->bd_info;
 579         oi = bi->bi_private;
 580         on = oi->oi_list;
 581
 582         for ( ; on; on = on->on_next ) {
 583                 if ( on->on_bi.bi_flags & SLAPO_BFLAG_DISABLED )
 584                         continue;
 585                 if ( on->on_bi.bi_acl_attribute ) {
 586                         /* NOTE: do not copy the structure until required */
 587                         if ( !SLAP_ISOVERLAY( op->o_bd ) ) {
 588                                 db = *op->o_bd;
 589                                 db.be_flags |= SLAP_DBFLAG_OVERLAY;
 590                                 op->o_bd = &db;
 591                         }
 592
 593                         op->o_bd->bd_info = (BackendInfo *)on;
 594                         rc = on->on_bi.bi_acl_attribute( op, target,
 595                                 entry_ndn, entry_at, vals, access );
 596                         if ( rc != SLAP_CB_CONTINUE ) break;
 597                 }
 598         }
 599
 600         if ( rc == SLAP_CB_CONTINUE ) {
 601                 BI_acl_attribute                *bi_acl_attribute;
 602
 603                 /* if the database structure was changed, o_bd points to a
 604                  * copy of the structure; put the original bd_info in place */
 605                 if ( SLAP_ISOVERLAY( op->o_bd ) ) {
 606                         op->o_bd->bd_info = oi->oi_orig;
 607                 }
 608
 609                 if ( oi->oi_orig->bi_acl_attribute ) {
 610                         bi_acl_attribute = oi->oi_orig->bi_acl_attribute;
 611                 } else {
 612                         bi_acl_attribute = backend_attribute;
 613                 }
 614
 615                 rc = bi_acl_attribute( op, target,
 616                         entry_ndn, entry_at, vals, access );
 617         }
 618         /* should not fall thru this far without anything happening... */
 619         if ( rc == SLAP_CB_CONTINUE ) {
 620                 /* access not allowed */
 621                 rc = 0;
 622         }
 623
 624         op->o_bd = be;
 625         if ( SLAP_ISOVERLAY( op->o_bd ) ) {
 626                 op->o_bd->bd_info = bi;
 627         }
 628
 629         return rc;
 630 }
 631
 632 int
 633 overlay_callback_after_backover( Operation *op, slap_callback *sc, int append )
 634 {
 635         slap_callback **scp;
 636
 637         for ( scp = &op->o_callback; *scp != NULL; scp = &(*scp)->sc_next ) {
 638                 if ( (*scp)->sc_response == over_back_response ) {
 639                         sc->sc_next = (*scp)->sc_next;
 640                         (*scp)->sc_next = sc;
 641                         return 0;
 642                 }
 643         }
 644
 645         if ( append ) {
 646                 *scp = sc;
 647                 return 0;
 648         }
 649
 650         return 1;
 651 }
 652
 653 /*
 654  * default return code in case of missing backend function
 655  * and overlay stack returning SLAP_CB_CONTINUE
 656  */
 657 static int op_rc[ op_last ] = {
 658         LDAP_UNWILLING_TO_PERFORM,      /* bind */
 659         LDAP_UNWILLING_TO_PERFORM,      /* unbind */
 660         LDAP_UNWILLING_TO_PERFORM,      /* search */
 661         SLAP_CB_CONTINUE,               /* compare; pass to frontend */
 662         LDAP_UNWILLING_TO_PERFORM,      /* modify */
 663         LDAP_UNWILLING_TO_PERFORM,      /* modrdn */
 664         LDAP_UNWILLING_TO_PERFORM,      /* add */
 665         LDAP_UNWILLING_TO_PERFORM,      /* delete */
 666         LDAP_UNWILLING_TO_PERFORM,      /* abandon */
 667         LDAP_UNWILLING_TO_PERFORM,      /* cancel */
 668         LDAP_UNWILLING_TO_PERFORM,      /* extended */
 669         LDAP_SUCCESS,                   /* aux_operational */
 670         LDAP_SUCCESS,                   /* aux_chk_referrals */
 671         SLAP_CB_CONTINUE                /* aux_chk_controls; pass to frontend */
 672 };
 673
 674 int overlay_op_walk(
 675         Operation *op,
 676         SlapReply *rs,
 677         slap_operation_t which,
 678         slap_overinfo *oi,
 679         slap_overinst *on
 680 )
 681 {
 682         BackendInfo *bi;
 683         int rc = SLAP_CB_CONTINUE;
 684
 685         for (; on; on=on->on_next ) {
 686                 if ( on->on_bi.bi_flags & SLAPO_BFLAG_DISABLED )
 687                         continue;
 688                 bi = &on->on_bi;
 689                 if ( (&bi->bi_op_bind)[ which ] ) {
 690                         op->o_bd->bd_info = (BackendInfo *)on;
 691                         rc = (&bi->bi_op_bind)[ which ]( op, rs );
 692                         if ( rc != SLAP_CB_CONTINUE ) break;
 693                 }
 694         }
 695         if ( rc == SLAP_CB_BYPASS )
 696                 rc = SLAP_CB_CONTINUE;
 697         /* if an overlay halted processing, make sure
 698          * any previously set cleanup handlers are run
 699          */
 700         if ( rc != SLAP_CB_CONTINUE )
 701                 goto cleanup;
 702
 703         bi = oi->oi_orig;
 704         if ( (&bi->bi_op_bind)[ which ] ) {
 705                 op->o_bd->bd_info = bi;
 706                 rc = (&bi->bi_op_bind)[ which ]( op, rs );
 707         }
 708         /* should not fall thru this far without anything happening... */
 709         if ( rc == SLAP_CB_CONTINUE ) {
 710                 rc = op_rc[ which ];
 711         }
 712
 713         /* The underlying backend didn't handle the request, make sure
 714          * overlay cleanup is processed.
 715          */
 716         if ( rc == LDAP_UNWILLING_TO_PERFORM ) {
 717                 slap_callback *sc_next;
 718 cleanup:
 719                 for ( ; op->o_callback && op->o_callback->sc_response !=
 720                         over_back_response; op->o_callback = sc_next ) {
 721                         sc_next = op->o_callback->sc_next;
 722                         if ( op->o_callback->sc_cleanup ) {
 723                                 op->o_callback->sc_cleanup( op, rs );
 724                         }
 725                 }
 726         }
 727         return rc;
 728 }
 729
 730 static int
 731 over_op_func(
 732         Operation *op,
 733         SlapReply *rs,
 734         slap_operation_t which
 735 )
 736 {
 737         slap_overinfo *oi;
 738         slap_overinst *on;
 739         BackendDB *be = op->o_bd, db;
 740         slap_callback **sc;
 741         slap_callback *cb;
 742         int rc = SLAP_CB_CONTINUE;
 743
 744         /* FIXME: used to happen for instance during abandon
 745          * when global overlays are used... */
 746         assert( op->o_bd != NULL );
 747
 748         oi = op->o_bd->bd_info->bi_private;
 749         on = oi->oi_list;
 750
 751         if ( !SLAP_ISOVERLAY( op->o_bd )) {
 752                 db = *op->o_bd;
 753                 db.be_flags |= SLAP_DBFLAG_OVERLAY;
 754                 op->o_bd = &db;
 755         }
 756         if ( op->o_tag != LDAP_REQ_ABANDON && op->o_tag != LDAP_REQ_UNBIND ) {
 757                 cb = (slap_callback *)op->o_tmpcalloc( 1, sizeof(slap_callback), op->o_tmpmemctx );
 758                 cb->sc_cleanup = NULL;
 759                 cb->sc_response = over_back_response;
 760                 cb->sc_writewait = NULL;
 761                 cb->sc_next = op->o_callback;
 762                 cb->sc_private = oi;
 763                 op->o_callback = cb;
 764         }
 765
 766         rc = overlay_op_walk( op, rs, which, oi, on );
 767         if ( rc != SLAPD_ASYNCOP && op->o_tag != LDAP_REQ_ABANDON && op->o_tag != LDAP_REQ_UNBIND ) {
 768                 for ( sc = &op->o_callback; *sc; sc = &(*sc)->sc_next ) {
 769                         if ( *sc == cb ) {
 770                                 *sc = cb->sc_next;
 771                                 op->o_tmpfree( cb, op->o_tmpmemctx );
 772                                 break;
 773                         }
 774                 }
 775         }
 776
 777         op->o_bd = be;
 778         return rc;
 779 }
 780
 781 static int
 782 over_op_bind( Operation *op, SlapReply *rs )
 783 {
 784         return over_op_func( op, rs, op_bind );
 785 }
 786
 787 static int
 788 over_op_unbind( Operation *op, SlapReply *rs )
 789 {
 790         return over_op_func( op, rs, op_unbind );
 791 }
 792
 793 static int
 794 over_op_search( Operation *op, SlapReply *rs )
 795 {
 796         return over_op_func( op, rs, op_search );
 797 }
 798
 799 static int
 800 over_op_compare( Operation *op, SlapReply *rs )
 801 {
 802         return over_op_func( op, rs, op_compare );
 803 }
 804
 805 static int
 806 over_op_modify( Operation *op, SlapReply *rs )
 807 {
 808         return over_op_func( op, rs, op_modify );
 809 }
 810
 811 static int
 812 over_op_modrdn( Operation *op, SlapReply *rs )
 813 {
 814         return over_op_func( op, rs, op_modrdn );
 815 }
 816
 817 static int
 818 over_op_add( Operation *op, SlapReply *rs )
 819 {
 820         return over_op_func( op, rs, op_add );
 821 }
 822
 823 static int
 824 over_op_delete( Operation *op, SlapReply *rs )
 825 {
 826         return over_op_func( op, rs, op_delete );
 827 }
 828
 829 static int
 830 over_op_abandon( Operation *op, SlapReply *rs )
 831 {
 832         return over_op_func( op, rs, op_abandon );
 833 }
 834
 835 static int
 836 over_op_cancel( Operation *op, SlapReply *rs )
 837 {
 838         return over_op_func( op, rs, op_cancel );
 839 }
 840
 841 static int
 842 over_op_extended( Operation *op, SlapReply *rs )
 843 {
 844         return over_op_func( op, rs, op_extended );
 845 }
 846
 847 static int
 848 over_aux_operational( Operation *op, SlapReply *rs )
 849 {
 850         return over_op_func( op, rs, op_aux_operational );
 851 }
 852
 853 static int
 854 over_aux_chk_referrals( Operation *op, SlapReply *rs )
 855 {
 856         return over_op_func( op, rs, op_aux_chk_referrals );
 857 }
 858
 859 static int
 860 over_aux_chk_controls( Operation *op, SlapReply *rs )
 861 {
 862         return over_op_func( op, rs, op_aux_chk_controls );
 863 }
 864
 865 enum conn_which {
 866         conn_init = 0,
 867         conn_destroy,
 868         conn_last
 869 };
 870
 871 static int
 872 over_connection_func(
 873         BackendDB       *bd,
 874         Connection      *conn,
 875         enum conn_which which
 876 )
 877 {
 878         slap_overinfo           *oi;
 879         slap_overinst           *on;
 880         BackendDB               db;
 881         int                     rc = SLAP_CB_CONTINUE;
 882         BI_connection_init      **func;
 883
 884         /* FIXME: used to happen for instance during abandon
 885          * when global overlays are used... */
 886         assert( bd != NULL );
 887
 888         oi = bd->bd_info->bi_private;
 889         on = oi->oi_list;
 890
 891         if ( !SLAP_ISOVERLAY( bd ) ) {
 892                 db = *bd;
 893                 db.be_flags |= SLAP_DBFLAG_OVERLAY;
 894                 bd = &db;
 895         }
 896
 897         for ( ; on; on = on->on_next ) {
 898                 if ( on->on_bi.bi_flags & SLAPO_BFLAG_DISABLED )
 899                         continue;
 900                 func = &on->on_bi.bi_connection_init;
 901                 if ( func[ which ] ) {
 902                         bd->bd_info = (BackendInfo *)on;
 903                         rc = func[ which ]( bd, conn );
 904                         if ( rc != SLAP_CB_CONTINUE ) break;
 905                 }
 906         }
 907
 908         func = &oi->oi_orig->bi_connection_init;
 909         if ( func[ which ] && rc == SLAP_CB_CONTINUE ) {
 910                 bd->bd_info = oi->oi_orig;
 911                 rc = func[ which ]( bd, conn );
 912         }
 913         /* should not fall thru this far without anything happening... */
 914         if ( rc == SLAP_CB_CONTINUE ) {
 915                 rc = LDAP_UNWILLING_TO_PERFORM;
 916         }
 917
 918         return rc;
 919 }
 920
 921 static int
 922 over_connection_init(
 923         BackendDB       *bd,
 924         Connection      *conn
 925 )
 926 {
 927         return over_connection_func( bd, conn, conn_init );
 928 }
 929
 930 static int
 931 over_connection_destroy(
 932         BackendDB       *bd,
 933         Connection      *conn
 934 )
 935 {
 936         return over_connection_func( bd, conn, conn_destroy );
 937 }
 938
 939 int
 940 overlay_register(
 941         slap_overinst *on
 942 )
 943 {
 944         slap_overinst   *tmp;
 945
 946         /* FIXME: check for duplicates? */
 947         for ( tmp = overlays; tmp != NULL; tmp = tmp->on_next ) {
 948                 if ( strcmp( on->on_bi.bi_type, tmp->on_bi.bi_type ) == 0 ) {
 949                         Debug( LDAP_DEBUG_ANY,
 950                                 "overlay_register(\"%s\"): "
 951                                 "name already in use.\n",
 952                                 on->on_bi.bi_type, 0, 0 );
 953                         return -1;
 954                 }
 955
 956                 if ( on->on_bi.bi_obsolete_names != NULL ) {
 957                         int     i;
 958
 959                         for ( i = 0; on->on_bi.bi_obsolete_names[ i ] != NULL; i++ ) {
 960                                 if ( strcmp( on->on_bi.bi_obsolete_names[ i ], tmp->on_bi.bi_type ) == 0 ) {
 961                                         Debug( LDAP_DEBUG_ANY,
 962                                                 "overlay_register(\"%s\"): "
 963                                                 "obsolete name \"%s\" already in use "
 964                                                 "by overlay \"%s\".\n",
 965                                                 on->on_bi.bi_type,
 966                                                 on->on_bi.bi_obsolete_names[ i ],
 967                                                 tmp->on_bi.bi_type );
 968                                         return -1;
 969                                 }
 970                         }
 971                 }
 972
 973                 if ( tmp->on_bi.bi_obsolete_names != NULL ) {
 974                         int     i;
 975
 976                         for ( i = 0; tmp->on_bi.bi_obsolete_names[ i ] != NULL; i++ ) {
 977                                 int     j;
 978
 979                                 if ( strcmp( on->on_bi.bi_type, tmp->on_bi.bi_obsolete_names[ i ] ) == 0 ) {
 980                                         Debug( LDAP_DEBUG_ANY,
 981                                                 "overlay_register(\"%s\"): "
 982                                                 "name already in use "
 983                                                 "as obsolete by overlay \"%s\".\n",
 984                                                 on->on_bi.bi_type,
 985                                                 tmp->on_bi.bi_obsolete_names[ i ], 0 );
 986                                         return -1;
 987                                 }
 988
 989                                 if ( on->on_bi.bi_obsolete_names != NULL ) {
 990                                         for ( j = 0; on->on_bi.bi_obsolete_names[ j ] != NULL; j++ ) {
 991                                                 if ( strcmp( on->on_bi.bi_obsolete_names[ j ], tmp->on_bi.bi_obsolete_names[ i ] ) == 0 ) {
 992                                                         Debug( LDAP_DEBUG_ANY,
 993                                                                 "overlay_register(\"%s\"): "
 994                                                                 "obsolete name \"%s\" already in use "
 995                                                                 "as obsolete by overlay \"%s\".\n",
 996                                                                 on->on_bi.bi_type,
 997                                                                 on->on_bi.bi_obsolete_names[ j ],
 998                                                                 tmp->on_bi.bi_type );
 999                                                         return -1;
1000                                                 }
1001                                         }
1002                                 }
1003                         }
1004                 }
1005         }
1006
1007         on->on_next = overlays;
1008         overlays = on;
1009         return 0;
1010 }
1011
1012 /*
1013  * iterator on registered overlays; overlay_next( NULL ) returns the first
1014  * overlay; subsequent calls with the previously returned value allow to
1015  * iterate over the entire list; returns NULL when no more overlays are
1016  * registered.
1017  */
1018
1019 slap_overinst *
1020 overlay_next(
1021         slap_overinst *on
1022 )
1023 {
1024         if ( on == NULL ) {
1025                 return overlays;
1026         }
1027
1028         return on->on_next;
1029 }
1030
1031 /*
1032  * returns a specific registered overlay based on the type; NULL if not
1033  * registered.
1034  */
1035
1036 slap_overinst *
1037 overlay_find( const char *over_type )
1038 {
1039         slap_overinst *on = overlays;
1040
1041         assert( over_type != NULL );
1042
1043         for ( ; on; on = on->on_next ) {
1044                 if ( strcmp( on->on_bi.bi_type, over_type ) == 0 ) {
1045                         goto foundit;
1046                 }
1047
1048                 if ( on->on_bi.bi_obsolete_names != NULL ) {
1049                         int     i;
1050
1051                         for ( i = 0; on->on_bi.bi_obsolete_names[ i ] != NULL; i++ ) {
1052                                 if ( strcmp( on->on_bi.bi_obsolete_names[ i ], over_type ) == 0 ) {
1053                                         Debug( LDAP_DEBUG_ANY,
1054                                                 "overlay_find(\"%s\"): "
1055                                                 "obsolete name for \"%s\".\n",
1056                                                 on->on_bi.bi_obsolete_names[ i ],
1057                                                 on->on_bi.bi_type, 0 );
1058                                         goto foundit;
1059                                 }
1060                         }
1061                 }
1062         }
1063
1064 foundit:;
1065         return on;
1066 }
1067
1068 static const char overtype[] = "over";
1069
1070 /*
1071  * returns TRUE (1) if the database is actually an overlay instance;
1072  * FALSE (0) otherwise.
1073  */
1074
1075 int
1076 overlay_is_over( BackendDB *be )
1077 {
1078         return be->bd_info->bi_type == overtype;
1079 }
1080
1081 /*
1082  * returns TRUE (1) if the given database is actually an overlay
1083  * instance and, somewhere in the list, contains the requested overlay;
1084  * FALSE (0) otherwise.
1085  */
1086
1087 int
1088 overlay_is_inst( BackendDB *be, const char *over_type )
1089 {
1090         slap_overinst   *on;
1091
1092         assert( be != NULL );
1093
1094         if ( !overlay_is_over( be ) ) {
1095                 return 0;
1096         }
1097
1098         on = ((slap_overinfo *)be->bd_info->bi_private)->oi_list;
1099         for ( ; on; on = on->on_next ) {
1100                 if ( strcmp( on->on_bi.bi_type, over_type ) == 0 ) {
1101                         return 1;
1102                 }
1103         }
1104
1105         return 0;
1106 }
1107
1108 int
1109 overlay_register_control( BackendDB *be, const char *oid )
1110 {
1111         int             gotit = 0;
1112         int             cid;
1113
1114         if ( slap_find_control_id( oid, &cid ) == LDAP_CONTROL_NOT_FOUND ) {
1115                 return -1;
1116         }
1117
1118         if ( SLAP_ISGLOBALOVERLAY( be ) ) {
1119                 BackendDB *bd;
1120
1121                 /* add to all backends... */
1122                 LDAP_STAILQ_FOREACH( bd, &backendDB, be_next ) {
1123                         if ( bd == be->bd_self ) {
1124                                 gotit = 1;
1125                         }
1126
1127                         /* overlays can be instantiated multiple times, use
1128                          * be_ctrls[ cid ] as an instance counter, so that the
1129                          * overlay's controls are only really disabled after the
1130                          * last instance called overlay_register_control() */
1131                         bd->be_ctrls[ cid ]++;
1132                         bd->be_ctrls[ SLAP_MAX_CIDS ] = 1;
1133                 }
1134
1135         }
1136
1137         if ( !gotit ) {
1138                 /* overlays can be instantiated multiple times, use
1139                  * be_ctrls[ cid ] as an instance counter, so that the
1140                  * overlay's controls are only really unregistered after the
1141                  * last instance called overlay_register_control() */
1142                 be->bd_self->be_ctrls[ cid ]++;
1143                 be->bd_self->be_ctrls[ SLAP_MAX_CIDS ] = 1;
1144         }
1145
1146         return 0;
1147 }
1148
1149 #ifdef SLAP_CONFIG_DELETE
1150 void
1151 overlay_unregister_control( BackendDB *be, const char *oid )
1152 {
1153         int             gotit = 0;
1154         int             cid;
1155
1156         if ( slap_find_control_id( oid, &cid ) == LDAP_CONTROL_NOT_FOUND ) {
1157                 return;
1158         }
1159
1160         if ( SLAP_ISGLOBALOVERLAY( be ) ) {
1161                 BackendDB *bd;
1162
1163                 /* remove from all backends... */
1164                 LDAP_STAILQ_FOREACH( bd, &backendDB, be_next ) {
1165                         if ( bd == be->bd_self ) {
1166                                 gotit = 1;
1167                         }
1168
1169                         bd->be_ctrls[ cid ]--;
1170                 }
1171         }
1172
1173         if ( !gotit ) {
1174                 be->bd_self->be_ctrls[ cid ]--;
1175         }
1176 }
1177 #endif /* SLAP_CONFIG_DELETE */
1178
1179 void
1180 overlay_destroy_one( BackendDB *be, slap_overinst *on )
1181 {
1182         slap_overinfo *oi = on->on_info;
1183         slap_overinst **oidx;
1184
1185         for ( oidx = &oi->oi_list; *oidx; oidx = &(*oidx)->on_next ) {
1186                 if ( *oidx == on ) {
1187                         *oidx = on->on_next;
1188                         if ( on->on_bi.bi_db_destroy ) {
1189                                 BackendInfo *bi_orig = be->bd_info;
1190                                 be->bd_info = (BackendInfo *)on;
1191                                 on->on_bi.bi_db_destroy( be, NULL );
1192                                 be->bd_info = bi_orig;
1193                         }
1194                         free( on );
1195                         break;
1196                 }
1197         }
1198 }
1199
1200 #ifdef SLAP_CONFIG_DELETE
1201 typedef struct ov_remove_ctx {
1202         BackendDB *be;
1203         slap_overinst *on;
1204 } ov_remove_ctx;
1205
1206 int
1207 overlay_remove_cb( Operation *op, SlapReply *rs )
1208 {
1209         ov_remove_ctx *rm_ctx = (ov_remove_ctx*) op->o_callback->sc_private;
1210         BackendInfo *bi_orig = rm_ctx->be->bd_info;
1211
1212         rm_ctx->be->bd_info = (BackendInfo*) rm_ctx->on;
1213
1214         if ( rm_ctx->on->on_bi.bi_db_close ) {
1215                 rm_ctx->on->on_bi.bi_db_close( rm_ctx->be, NULL );
1216         }
1217         if ( rm_ctx->on->on_bi.bi_db_destroy ) {
1218                 rm_ctx->on->on_bi.bi_db_destroy( rm_ctx->be, NULL );
1219         }
1220
1221         /* clean up after removing last overlay */
1222         if ( ! rm_ctx->on->on_info->oi_list ) {
1223                 /* reset db flags and bd_info to orig */
1224                 SLAP_DBFLAGS( rm_ctx->be ) &= ~SLAP_DBFLAG_GLOBAL_OVERLAY;
1225                 rm_ctx->be->bd_info = rm_ctx->on->on_info->oi_orig;
1226                 ch_free(rm_ctx->on->on_info);
1227         } else {
1228                 rm_ctx->be->bd_info = bi_orig;
1229         }
1230         free( rm_ctx->on );
1231         op->o_tmpfree(rm_ctx, op->o_tmpmemctx);
1232         return SLAP_CB_CONTINUE;
1233 }
1234
1235 void
1236 overlay_remove( BackendDB *be, slap_overinst *on, Operation *op )
1237 {
1238         slap_overinfo *oi = on->on_info;
1239         slap_overinst **oidx;
1240         ov_remove_ctx *rm_ctx;
1241         slap_callback *rm_cb, *cb;
1242
1243         /* remove overlay from oi_list */
1244         for ( oidx = &oi->oi_list; *oidx; oidx = &(*oidx)->on_next ) {
1245                 if ( *oidx == on ) {
1246                         *oidx = on->on_next;
1247                         break;
1248                 }
1249         }
1250
1251         /* The db_close and db_destroy handlers to cleanup a release
1252          * the overlay's resources are called from the cleanup callback
1253          */
1254         rm_ctx = op->o_tmpalloc( sizeof( ov_remove_ctx ), op->o_tmpmemctx );
1255         rm_ctx->be = be;
1256         rm_ctx->on = on;
1257
1258         rm_cb = op->o_tmpalloc( sizeof( slap_callback ), op->o_tmpmemctx );
1259         rm_cb->sc_next = NULL;
1260         rm_cb->sc_cleanup = overlay_remove_cb;
1261         rm_cb->sc_response = NULL;
1262         rm_cb->sc_private = (void*) rm_ctx;
1263         rm_cb->sc_writewait = NULL;
1264
1265         /* Append callback to the end of the list */
1266         if ( !op->o_callback ) {
1267                 op->o_callback = rm_cb;
1268         } else {
1269                 for ( cb = op->o_callback; cb->sc_next; cb = cb->sc_next );
1270                 cb->sc_next = rm_cb;
1271         }
1272 }
1273 #endif /* SLAP_CONFIG_DELETE */
1274
1275 void
1276 overlay_insert( BackendDB *be, slap_overinst *on2, slap_overinst ***prev,
1277         int idx )
1278 {
1279         slap_overinfo *oi = (slap_overinfo *)be->bd_info;
1280
1281         if ( idx == -1 ) {
1282                 on2->on_next = oi->oi_list;
1283                 oi->oi_list = on2;
1284         } else {
1285                 int i, novs;
1286                 slap_overinst *on, **prev;
1287
1288                 /* Since the list is in reverse order and is singly linked,
1289                  * we have to count the overlays and then insert backwards.
1290                  * Adding on overlay at a specific point should be a pretty
1291                  * infrequent occurrence.
1292                  */
1293                 novs = 0;
1294                 for ( on = oi->oi_list; on; on=on->on_next )
1295                         novs++;
1296
1297                 if (idx > novs)
1298                         idx = 0;
1299                 else
1300                         idx = novs - idx;
1301
1302                 /* advance to insertion point */
1303                 prev = &oi->oi_list;
1304                 for ( i=0; i<idx; i++ ) {
1305                         on = *prev;
1306                         prev = &on->on_next;
1307                 }
1308                 /* insert */
1309                 on2->on_next = *prev;
1310                 *prev = on2;
1311         }
1312 }
1313
1314 void
1315 overlay_move( BackendDB *be, slap_overinst *on, int idx )
1316 {
1317         slap_overinfo *oi = (slap_overinfo *)be->bd_info;
1318         slap_overinst **onp;
1319
1320         for (onp = &oi->oi_list; *onp; onp= &(*onp)->on_next) {
1321                 if ( *onp == on ) {
1322                         *onp = on->on_next;
1323                         break;
1324                 }
1325         }
1326         overlay_insert( be, on, &onp, idx );
1327 }
1328
1329 /* add an overlay to a particular backend. */
1330 int
1331 overlay_config( BackendDB *be, const char *ov, int idx, BackendInfo **res, ConfigReply *cr )
1332 {
1333         slap_overinst *on = NULL, *on2 = NULL, **prev;
1334         slap_overinfo *oi = NULL;
1335         BackendInfo *bi = NULL;
1336
1337         if ( res )
1338                 *res = NULL;
1339
1340         on = overlay_find( ov );
1341         if ( !on ) {
1342                 Debug( LDAP_DEBUG_ANY, "overlay \"%s\" not found\n", ov, 0, 0 );
1343                 return 1;
1344         }
1345
1346         /* If this is the first overlay on this backend, set up the
1347          * overlay info structure
1348          */
1349         if ( !overlay_is_over( be ) ) {
1350                 int     isglobal = 0;
1351
1352                 /* NOTE: the first time a global overlay is configured,
1353                  * frontendDB gets this flag; it is used later by overlays
1354                  * to determine if they're stacked on top of the frontendDB */
1355                 if ( be->bd_info == frontendDB->bd_info || SLAP_ISGLOBALOVERLAY( be ) ) {
1356                         isglobal = 1;
1357                         if ( on->on_bi.bi_flags & SLAPO_BFLAG_DBONLY ) {
1358                                 Debug( LDAP_DEBUG_ANY, "overlay_config(): "
1359                                         "overlay \"%s\" cannot be global.\n",
1360                                         ov, 0, 0 );
1361                                 return 1;
1362                         }
1363
1364                 } else if ( on->on_bi.bi_flags & SLAPO_BFLAG_GLOBONLY ) {
1365                         Debug( LDAP_DEBUG_ANY, "overlay_config(): "
1366                                 "overlay \"%s\" can only be global.\n",
1367                                 ov, 0, 0 );
1368                         return 1;
1369                 }
1370
1371                 oi = ch_malloc( sizeof( slap_overinfo ) );
1372                 oi->oi_orig = be->bd_info;
1373                 oi->oi_bi = *be->bd_info;
1374                 oi->oi_origdb = be;
1375
1376                 if ( isglobal ) {
1377                         SLAP_DBFLAGS( be ) |= SLAP_DBFLAG_GLOBAL_OVERLAY;
1378                 }
1379
1380                 /* Save a pointer to ourself in bi_private.
1381                  */
1382                 oi->oi_bi.bi_private = oi;
1383                 oi->oi_list = NULL;
1384                 bi = (BackendInfo *)oi;
1385
1386                 bi->bi_type = (char *)overtype;
1387
1388                 bi->bi_db_config = over_db_config;
1389                 bi->bi_db_open = over_db_open;
1390                 bi->bi_db_close = over_db_close;
1391                 bi->bi_db_destroy = over_db_destroy;
1392
1393                 bi->bi_op_bind = over_op_bind;
1394                 bi->bi_op_unbind = over_op_unbind;
1395                 bi->bi_op_search = over_op_search;
1396                 bi->bi_op_compare = over_op_compare;
1397                 bi->bi_op_modify = over_op_modify;
1398                 bi->bi_op_modrdn = over_op_modrdn;
1399                 bi->bi_op_add = over_op_add;
1400                 bi->bi_op_delete = over_op_delete;
1401                 bi->bi_op_abandon = over_op_abandon;
1402                 bi->bi_op_cancel = over_op_cancel;
1403
1404                 bi->bi_extended = over_op_extended;
1405
1406                 /*
1407                  * this is fine because it has the same
1408                  * args of the operations; we need to rework
1409                  * all the hooks to share the same args
1410                  * of the operations...
1411                  */
1412                 bi->bi_operational = over_aux_operational;
1413                 bi->bi_chk_referrals = over_aux_chk_referrals;
1414                 bi->bi_chk_controls = over_aux_chk_controls;
1415
1416                 /* these have specific arglists */
1417                 bi->bi_entry_get_rw = over_entry_get_rw;
1418                 bi->bi_entry_release_rw = over_entry_release_rw;
1419                 bi->bi_access_allowed = over_access_allowed;
1420                 bi->bi_acl_group = over_acl_group;
1421                 bi->bi_acl_attribute = over_acl_attribute;
1422
1423                 bi->bi_connection_init = over_connection_init;
1424                 bi->bi_connection_destroy = over_connection_destroy;
1425
1426                 be->bd_info = bi;
1427
1428         } else {
1429                 if ( overlay_is_inst( be, ov ) ) {
1430                         if ( SLAPO_SINGLE( be ) ) {
1431                                 Debug( LDAP_DEBUG_ANY, "overlay_config(): "
1432                                         "overlay \"%s\" already in list\n",
1433                                         ov, 0, 0 );
1434                                 return 1;
1435                         }
1436                 }
1437
1438                 oi = be->bd_info->bi_private;
1439         }
1440
1441         /* Insert new overlay into list. By default overlays are
1442          * added to head of list and executed in LIFO order.
1443          */
1444         on2 = ch_calloc( 1, sizeof(slap_overinst) );
1445         *on2 = *on;
1446         on2->on_info = oi;
1447
1448         prev = &oi->oi_list;
1449         /* Do we need to find the insertion point? */
1450         if ( idx >= 0 ) {
1451                 int i;
1452
1453                 /* count current overlays */
1454                 for ( i=0, on=oi->oi_list; on; on=on->on_next, i++ );
1455
1456                 /* are we just appending a new one? */
1457                 if ( idx >= i )
1458                         idx = -1;
1459         }
1460         overlay_insert( be, on2, &prev, idx );
1461
1462         /* Any initialization needed? */
1463         if ( on2->on_bi.bi_db_init ) {
1464                 int rc;
1465                 be->bd_info = (BackendInfo *)on2;
1466                 rc = on2->on_bi.bi_db_init( be, cr);
1467                 be->bd_info = (BackendInfo *)oi;
1468                 if ( rc ) {
1469                         *prev = on2->on_next;
1470                         ch_free( on2 );
1471                         on2 = NULL;
1472                         return rc;
1473                 }
1474         }
1475
1476         if ( res )
1477                 *res = &on2->on_bi;
1478
1479         return 0;
1480 }