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_cleanup( Operation *op, SlapReply *rs )
 732 {
 733         slap_callback *cb = op->o_callback;
 734         if ( rs->sr_type == REP_RESULT && cb != NULL) {
 735                 op->o_callback = cb->sc_next;
 736                 op->o_tmpfree( cb, op->o_tmpmemctx );
 737         }
 738 }
 739
 740 static int
 741 over_op_func(
 742         Operation *op,
 743         SlapReply *rs,
 744         slap_operation_t which
 745 )
 746 {
 747         slap_overinfo *oi;
 748         slap_overinst *on;
 749         BackendDB *be = op->o_bd, db;
 750         slap_callback **sc;
 751         slap_callback *cb;
 752         int rc = SLAP_CB_CONTINUE;
 753
 754         /* FIXME: used to happen for instance during abandon
 755          * when global overlays are used... */
 756         assert( op->o_bd != NULL );
 757
 758         oi = op->o_bd->bd_info->bi_private;
 759         on = oi->oi_list;
 760
 761         if ( !SLAP_ISOVERLAY( op->o_bd )) {
 762                 db = *op->o_bd;
 763                 db.be_flags |= SLAP_DBFLAG_OVERLAY;
 764                 op->o_bd = &db;
 765         }
 766         if ( op->o_tag != LDAP_REQ_ABANDON && op->o_tag != LDAP_REQ_UNBIND ) {
 767                 cb = (slap_callback *)op->o_tmpcalloc( 1, sizeof(slap_callback), op->o_tmpmemctx );
 768                 cb->sc_cleanup = over_op_func_cleanup;
 769                 cb->sc_response = over_back_response;
 770                 cb->sc_writewait = NULL;
 771                 cb->sc_next = op->o_callback;
 772                 cb->sc_private = oi;
 773                 op->o_callback = cb;
 774         }
 775
 776         rc = overlay_op_walk( op, rs, which, oi, on );
 777         if ( rc != SLAPD_ASYNCOP && op->o_tag != LDAP_REQ_ABANDON && op->o_tag != LDAP_REQ_UNBIND ) {
 778                 for ( sc = &op->o_callback; *sc; sc = &(*sc)->sc_next ) {
 779                         if ( *sc == cb ) {
 780                                 *sc = cb->sc_next;
 781                                 op->o_tmpfree( cb, op->o_tmpmemctx );
 782                                 break;
 783                         }
 784                 }
 785         }
 786
 787         op->o_bd = be;
 788         return rc;
 789 }
 790
 791 static int
 792 over_op_bind( Operation *op, SlapReply *rs )
 793 {
 794         return over_op_func( op, rs, op_bind );
 795 }
 796
 797 static int
 798 over_op_unbind( Operation *op, SlapReply *rs )
 799 {
 800         return over_op_func( op, rs, op_unbind );
 801 }
 802
 803 static int
 804 over_op_search( Operation *op, SlapReply *rs )
 805 {
 806         return over_op_func( op, rs, op_search );
 807 }
 808
 809 static int
 810 over_op_compare( Operation *op, SlapReply *rs )
 811 {
 812         return over_op_func( op, rs, op_compare );
 813 }
 814
 815 static int
 816 over_op_modify( Operation *op, SlapReply *rs )
 817 {
 818         return over_op_func( op, rs, op_modify );
 819 }
 820
 821 static int
 822 over_op_modrdn( Operation *op, SlapReply *rs )
 823 {
 824         return over_op_func( op, rs, op_modrdn );
 825 }
 826
 827 static int
 828 over_op_add( Operation *op, SlapReply *rs )
 829 {
 830         return over_op_func( op, rs, op_add );
 831 }
 832
 833 static int
 834 over_op_delete( Operation *op, SlapReply *rs )
 835 {
 836         return over_op_func( op, rs, op_delete );
 837 }
 838
 839 static int
 840 over_op_abandon( Operation *op, SlapReply *rs )
 841 {
 842         return over_op_func( op, rs, op_abandon );
 843 }
 844
 845 static int
 846 over_op_cancel( Operation *op, SlapReply *rs )
 847 {
 848         return over_op_func( op, rs, op_cancel );
 849 }
 850
 851 static int
 852 over_op_extended( Operation *op, SlapReply *rs )
 853 {
 854         return over_op_func( op, rs, op_extended );
 855 }
 856
 857 static int
 858 over_aux_operational( Operation *op, SlapReply *rs )
 859 {
 860         return over_op_func( op, rs, op_aux_operational );
 861 }
 862
 863 static int
 864 over_aux_chk_referrals( Operation *op, SlapReply *rs )
 865 {
 866         return over_op_func( op, rs, op_aux_chk_referrals );
 867 }
 868
 869 static int
 870 over_aux_chk_controls( Operation *op, SlapReply *rs )
 871 {
 872         return over_op_func( op, rs, op_aux_chk_controls );
 873 }
 874
 875 enum conn_which {
 876         conn_init = 0,
 877         conn_destroy,
 878         conn_last
 879 };
 880
 881 static int
 882 over_connection_func(
 883         BackendDB       *bd,
 884         Connection      *conn,
 885         enum conn_which which
 886 )
 887 {
 888         slap_overinfo           *oi;
 889         slap_overinst           *on;
 890         BackendDB               db;
 891         int                     rc = SLAP_CB_CONTINUE;
 892         BI_connection_init      **func;
 893
 894         /* FIXME: used to happen for instance during abandon
 895          * when global overlays are used... */
 896         assert( bd != NULL );
 897
 898         oi = bd->bd_info->bi_private;
 899         on = oi->oi_list;
 900
 901         if ( !SLAP_ISOVERLAY( bd ) ) {
 902                 db = *bd;
 903                 db.be_flags |= SLAP_DBFLAG_OVERLAY;
 904                 bd = &db;
 905         }
 906
 907         for ( ; on; on = on->on_next ) {
 908                 if ( on->on_bi.bi_flags & SLAPO_BFLAG_DISABLED )
 909                         continue;
 910                 func = &on->on_bi.bi_connection_init;
 911                 if ( func[ which ] ) {
 912                         bd->bd_info = (BackendInfo *)on;
 913                         rc = func[ which ]( bd, conn );
 914                         if ( rc != SLAP_CB_CONTINUE ) break;
 915                 }
 916         }
 917
 918         func = &oi->oi_orig->bi_connection_init;
 919         if ( func[ which ] && rc == SLAP_CB_CONTINUE ) {
 920                 bd->bd_info = oi->oi_orig;
 921                 rc = func[ which ]( bd, conn );
 922         }
 923         /* should not fall thru this far without anything happening... */
 924         if ( rc == SLAP_CB_CONTINUE ) {
 925                 rc = LDAP_UNWILLING_TO_PERFORM;
 926         }
 927
 928         return rc;
 929 }
 930
 931 static int
 932 over_connection_init(
 933         BackendDB       *bd,
 934         Connection      *conn
 935 )
 936 {
 937         return over_connection_func( bd, conn, conn_init );
 938 }
 939
 940 static int
 941 over_connection_destroy(
 942         BackendDB       *bd,
 943         Connection      *conn
 944 )
 945 {
 946         return over_connection_func( bd, conn, conn_destroy );
 947 }
 948
 949 int
 950 overlay_register(
 951         slap_overinst *on
 952 )
 953 {
 954         slap_overinst   *tmp;
 955
 956         /* FIXME: check for duplicates? */
 957         for ( tmp = overlays; tmp != NULL; tmp = tmp->on_next ) {
 958                 if ( strcmp( on->on_bi.bi_type, tmp->on_bi.bi_type ) == 0 ) {
 959                         Debug( LDAP_DEBUG_ANY,
 960                                 "overlay_register(\"%s\"): "
 961                                 "name already in use.\n",
 962                                 on->on_bi.bi_type, 0, 0 );
 963                         return -1;
 964                 }
 965
 966                 if ( on->on_bi.bi_obsolete_names != NULL ) {
 967                         int     i;
 968
 969                         for ( i = 0; on->on_bi.bi_obsolete_names[ i ] != NULL; i++ ) {
 970                                 if ( strcmp( on->on_bi.bi_obsolete_names[ i ], tmp->on_bi.bi_type ) == 0 ) {
 971                                         Debug( LDAP_DEBUG_ANY,
 972                                                 "overlay_register(\"%s\"): "
 973                                                 "obsolete name \"%s\" already in use "
 974                                                 "by overlay \"%s\".\n",
 975                                                 on->on_bi.bi_type,
 976                                                 on->on_bi.bi_obsolete_names[ i ],
 977                                                 tmp->on_bi.bi_type );
 978                                         return -1;
 979                                 }
 980                         }
 981                 }
 982
 983                 if ( tmp->on_bi.bi_obsolete_names != NULL ) {
 984                         int     i;
 985
 986                         for ( i = 0; tmp->on_bi.bi_obsolete_names[ i ] != NULL; i++ ) {
 987                                 int     j;
 988
 989                                 if ( strcmp( on->on_bi.bi_type, tmp->on_bi.bi_obsolete_names[ i ] ) == 0 ) {
 990                                         Debug( LDAP_DEBUG_ANY,
 991                                                 "overlay_register(\"%s\"): "
 992                                                 "name already in use "
 993                                                 "as obsolete by overlay \"%s\".\n",
 994                                                 on->on_bi.bi_type,
 995                                                 tmp->on_bi.bi_obsolete_names[ i ], 0 );
 996                                         return -1;
 997                                 }
 998
 999                                 if ( on->on_bi.bi_obsolete_names != NULL ) {
1000                                         for ( j = 0; on->on_bi.bi_obsolete_names[ j ] != NULL; j++ ) {
1001                                                 if ( strcmp( on->on_bi.bi_obsolete_names[ j ], tmp->on_bi.bi_obsolete_names[ i ] ) == 0 ) {
1002                                                         Debug( LDAP_DEBUG_ANY,
1003                                                                 "overlay_register(\"%s\"): "
1004                                                                 "obsolete name \"%s\" already in use "
1005                                                                 "as obsolete by overlay \"%s\".\n",
1006                                                                 on->on_bi.bi_type,
1007                                                                 on->on_bi.bi_obsolete_names[ j ],
1008                                                                 tmp->on_bi.bi_type );
1009                                                         return -1;
1010                                                 }
1011                                         }
1012                                 }
1013                         }
1014                 }
1015         }
1016
1017         on->on_next = overlays;
1018         overlays = on;
1019         return 0;
1020 }
1021
1022 /*
1023  * iterator on registered overlays; overlay_next( NULL ) returns the first
1024  * overlay; subsequent calls with the previously returned value allow to
1025  * iterate over the entire list; returns NULL when no more overlays are
1026  * registered.
1027  */
1028
1029 slap_overinst *
1030 overlay_next(
1031         slap_overinst *on
1032 )
1033 {
1034         if ( on == NULL ) {
1035                 return overlays;
1036         }
1037
1038         return on->on_next;
1039 }
1040
1041 /*
1042  * returns a specific registered overlay based on the type; NULL if not
1043  * registered.
1044  */
1045
1046 slap_overinst *
1047 overlay_find( const char *over_type )
1048 {
1049         slap_overinst *on = overlays;
1050
1051         assert( over_type != NULL );
1052
1053         for ( ; on; on = on->on_next ) {
1054                 if ( strcmp( on->on_bi.bi_type, over_type ) == 0 ) {
1055                         goto foundit;
1056                 }
1057
1058                 if ( on->on_bi.bi_obsolete_names != NULL ) {
1059                         int     i;
1060
1061                         for ( i = 0; on->on_bi.bi_obsolete_names[ i ] != NULL; i++ ) {
1062                                 if ( strcmp( on->on_bi.bi_obsolete_names[ i ], over_type ) == 0 ) {
1063                                         Debug( LDAP_DEBUG_ANY,
1064                                                 "overlay_find(\"%s\"): "
1065                                                 "obsolete name for \"%s\".\n",
1066                                                 on->on_bi.bi_obsolete_names[ i ],
1067                                                 on->on_bi.bi_type, 0 );
1068                                         goto foundit;
1069                                 }
1070                         }
1071                 }
1072         }
1073
1074 foundit:;
1075         return on;
1076 }
1077
1078 static const char overtype[] = "over";
1079
1080 /*
1081  * returns TRUE (1) if the database is actually an overlay instance;
1082  * FALSE (0) otherwise.
1083  */
1084
1085 int
1086 overlay_is_over( BackendDB *be )
1087 {
1088         return be->bd_info->bi_type == overtype;
1089 }
1090
1091 /*
1092  * returns TRUE (1) if the given database is actually an overlay
1093  * instance and, somewhere in the list, contains the requested overlay;
1094  * FALSE (0) otherwise.
1095  */
1096
1097 int
1098 overlay_is_inst( BackendDB *be, const char *over_type )
1099 {
1100         slap_overinst   *on;
1101
1102         assert( be != NULL );
1103
1104         if ( !overlay_is_over( be ) ) {
1105                 return 0;
1106         }
1107
1108         on = ((slap_overinfo *)be->bd_info->bi_private)->oi_list;
1109         for ( ; on; on = on->on_next ) {
1110                 if ( strcmp( on->on_bi.bi_type, over_type ) == 0 ) {
1111                         return 1;
1112                 }
1113         }
1114
1115         return 0;
1116 }
1117
1118 int
1119 overlay_register_control( BackendDB *be, const char *oid )
1120 {
1121         int             gotit = 0;
1122         int             cid;
1123
1124         if ( slap_find_control_id( oid, &cid ) == LDAP_CONTROL_NOT_FOUND ) {
1125                 return -1;
1126         }
1127
1128         if ( SLAP_ISGLOBALOVERLAY( be ) ) {
1129                 BackendDB *bd;
1130
1131                 /* add to all backends... */
1132                 LDAP_STAILQ_FOREACH( bd, &backendDB, be_next ) {
1133                         if ( bd == be->bd_self ) {
1134                                 gotit = 1;
1135                         }
1136
1137                         /* overlays can be instanciated multiple times, use
1138                          * be_ctrls[ cid ] as an instance counter, so that the
1139                          * overlay's controls are only really disabled after the
1140                          * last instance called overlay_register_control() */
1141                         bd->be_ctrls[ cid ]++;
1142                         bd->be_ctrls[ SLAP_MAX_CIDS ] = 1;
1143                 }
1144
1145         }
1146
1147         if ( !gotit ) {
1148                 /* overlays can be instanciated multiple times, use
1149                  * be_ctrls[ cid ] as an instance counter, so that the
1150                  * overlay's controls are only really unregistered after the
1151                  * last instance called overlay_register_control() */
1152                 be->bd_self->be_ctrls[ cid ]++;
1153                 be->bd_self->be_ctrls[ SLAP_MAX_CIDS ] = 1;
1154         }
1155
1156         return 0;
1157 }
1158
1159 #ifdef SLAP_CONFIG_DELETE
1160 void
1161 overlay_unregister_control( BackendDB *be, const char *oid )
1162 {
1163         int             gotit = 0;
1164         int             cid;
1165
1166         if ( slap_find_control_id( oid, &cid ) == LDAP_CONTROL_NOT_FOUND ) {
1167                 return;
1168         }
1169
1170         if ( SLAP_ISGLOBALOVERLAY( be ) ) {
1171                 BackendDB *bd;
1172
1173                 /* remove from all backends... */
1174                 LDAP_STAILQ_FOREACH( bd, &backendDB, be_next ) {
1175                         if ( bd == be->bd_self ) {
1176                                 gotit = 1;
1177                         }
1178
1179                         bd->be_ctrls[ cid ]--;
1180                 }
1181         }
1182
1183         if ( !gotit ) {
1184                 be->bd_self->be_ctrls[ cid ]--;
1185         }
1186 }
1187 #endif /* SLAP_CONFIG_DELETE */
1188
1189 void
1190 overlay_destroy_one( BackendDB *be, slap_overinst *on )
1191 {
1192         slap_overinfo *oi = on->on_info;
1193         slap_overinst **oidx;
1194
1195         for ( oidx = &oi->oi_list; *oidx; oidx = &(*oidx)->on_next ) {
1196                 if ( *oidx == on ) {
1197                         *oidx = on->on_next;
1198                         if ( on->on_bi.bi_db_destroy ) {
1199                                 BackendInfo *bi_orig = be->bd_info;
1200                                 be->bd_info = (BackendInfo *)on;
1201                                 on->on_bi.bi_db_destroy( be, NULL );
1202                                 be->bd_info = bi_orig;
1203                         }
1204                         free( on );
1205                         break;
1206                 }
1207         }
1208 }
1209
1210 #ifdef SLAP_CONFIG_DELETE
1211 typedef struct ov_remove_ctx {
1212         BackendDB *be;
1213         slap_overinst *on;
1214 } ov_remove_ctx;
1215
1216 int
1217 overlay_remove_cb( Operation *op, SlapReply *rs )
1218 {
1219         ov_remove_ctx *rm_ctx = (ov_remove_ctx*) op->o_callback->sc_private;
1220         BackendInfo *bi_orig = rm_ctx->be->bd_info;
1221
1222         rm_ctx->be->bd_info = (BackendInfo*) rm_ctx->on;
1223
1224         if ( rm_ctx->on->on_bi.bi_db_close ) {
1225                 rm_ctx->on->on_bi.bi_db_close( rm_ctx->be, NULL );
1226         }
1227         if ( rm_ctx->on->on_bi.bi_db_destroy ) {
1228                 rm_ctx->on->on_bi.bi_db_destroy( rm_ctx->be, NULL );
1229         }
1230
1231         /* clean up after removing last overlay */
1232         if ( ! rm_ctx->on->on_info->oi_list ) {
1233                 /* reset db flags and bd_info to orig */
1234                 SLAP_DBFLAGS( rm_ctx->be ) &= ~SLAP_DBFLAG_GLOBAL_OVERLAY;
1235                 rm_ctx->be->bd_info = rm_ctx->on->on_info->oi_orig;
1236                 ch_free(rm_ctx->on->on_info);
1237         } else {
1238                 rm_ctx->be->bd_info = bi_orig;
1239         }
1240         free( rm_ctx->on );
1241         op->o_tmpfree(rm_ctx, op->o_tmpmemctx);
1242         return SLAP_CB_CONTINUE;
1243 }
1244
1245 void
1246 overlay_remove( BackendDB *be, slap_overinst *on, Operation *op )
1247 {
1248         slap_overinfo *oi = on->on_info;
1249         slap_overinst **oidx;
1250         ov_remove_ctx *rm_ctx;
1251         slap_callback *rm_cb, *cb;
1252
1253         /* remove overlay from oi_list */
1254         for ( oidx = &oi->oi_list; *oidx; oidx = &(*oidx)->on_next ) {
1255                 if ( *oidx == on ) {
1256                         *oidx = on->on_next;
1257                         break;
1258                 }
1259         }
1260
1261         /* The db_close and db_destroy handlers to cleanup a release
1262          * the overlay's resources are called from the cleanup callback
1263          */
1264         rm_ctx = op->o_tmpalloc( sizeof( ov_remove_ctx ), op->o_tmpmemctx );
1265         rm_ctx->be = be;
1266         rm_ctx->on = on;
1267
1268         rm_cb = op->o_tmpalloc( sizeof( slap_callback ), op->o_tmpmemctx );
1269         rm_cb->sc_next = NULL;
1270         rm_cb->sc_cleanup = overlay_remove_cb;
1271         rm_cb->sc_response = NULL;
1272         rm_cb->sc_private = (void*) rm_ctx;
1273         rm_cb->sc_writewait = NULL;
1274
1275         /* Append callback to the end of the list */
1276         if ( !op->o_callback ) {
1277                 op->o_callback = rm_cb;
1278         } else {
1279                 for ( cb = op->o_callback; cb->sc_next; cb = cb->sc_next );
1280                 cb->sc_next = rm_cb;
1281         }
1282 }
1283 #endif /* SLAP_CONFIG_DELETE */
1284
1285 void
1286 overlay_insert( BackendDB *be, slap_overinst *on2, slap_overinst ***prev,
1287         int idx )
1288 {
1289         slap_overinfo *oi = (slap_overinfo *)be->bd_info;
1290
1291         if ( idx == -1 ) {
1292                 on2->on_next = oi->oi_list;
1293                 oi->oi_list = on2;
1294         } else {
1295                 int i, novs;
1296                 slap_overinst *on, **prev;
1297
1298                 /* Since the list is in reverse order and is singly linked,
1299                  * we have to count the overlays and then insert backwards.
1300                  * Adding on overlay at a specific point should be a pretty
1301                  * infrequent occurrence.
1302                  */
1303                 novs = 0;
1304                 for ( on = oi->oi_list; on; on=on->on_next )
1305                         novs++;
1306
1307                 if (idx > novs)
1308                         idx = 0;
1309                 else
1310                         idx = novs - idx;
1311
1312                 /* advance to insertion point */
1313                 prev = &oi->oi_list;
1314                 for ( i=0; i<idx; i++ ) {
1315                         on = *prev;
1316                         prev = &on->on_next;
1317                 }
1318                 /* insert */
1319                 on2->on_next = *prev;
1320                 *prev = on2;
1321         }
1322 }
1323
1324 void
1325 overlay_move( BackendDB *be, slap_overinst *on, int idx )
1326 {
1327         slap_overinfo *oi = (slap_overinfo *)be->bd_info;
1328         slap_overinst **onp;
1329
1330         for (onp = &oi->oi_list; *onp; onp= &(*onp)->on_next) {
1331                 if ( *onp == on ) {
1332                         *onp = on->on_next;
1333                         break;
1334                 }
1335         }
1336         overlay_insert( be, on, &onp, idx );
1337 }
1338
1339 /* add an overlay to a particular backend. */
1340 int
1341 overlay_config( BackendDB *be, const char *ov, int idx, BackendInfo **res, ConfigReply *cr )
1342 {
1343         slap_overinst *on = NULL, *on2 = NULL, **prev;
1344         slap_overinfo *oi = NULL;
1345         BackendInfo *bi = NULL;
1346
1347         if ( res )
1348                 *res = NULL;
1349
1350         on = overlay_find( ov );
1351         if ( !on ) {
1352                 Debug( LDAP_DEBUG_ANY, "overlay \"%s\" not found\n", ov, 0, 0 );
1353                 return 1;
1354         }
1355
1356         /* If this is the first overlay on this backend, set up the
1357          * overlay info structure
1358          */
1359         if ( !overlay_is_over( be ) ) {
1360                 int     isglobal = 0;
1361
1362                 /* NOTE: the first time a global overlay is configured,
1363                  * frontendDB gets this flag; it is used later by overlays
1364                  * to determine if they're stacked on top of the frontendDB */
1365                 if ( be->bd_info == frontendDB->bd_info || SLAP_ISGLOBALOVERLAY( be ) ) {
1366                         isglobal = 1;
1367                         if ( on->on_bi.bi_flags & SLAPO_BFLAG_DBONLY ) {
1368                                 Debug( LDAP_DEBUG_ANY, "overlay_config(): "
1369                                         "overlay \"%s\" cannot be global.\n",
1370                                         ov, 0, 0 );
1371                                 return 1;
1372                         }
1373
1374                 } else if ( on->on_bi.bi_flags & SLAPO_BFLAG_GLOBONLY ) {
1375                         Debug( LDAP_DEBUG_ANY, "overlay_config(): "
1376                                 "overlay \"%s\" can only be global.\n",
1377                                 ov, 0, 0 );
1378                         return 1;
1379                 }
1380
1381                 oi = ch_malloc( sizeof( slap_overinfo ) );
1382                 oi->oi_orig = be->bd_info;
1383                 oi->oi_bi = *be->bd_info;
1384                 oi->oi_origdb = be;
1385
1386                 if ( isglobal ) {
1387                         SLAP_DBFLAGS( be ) |= SLAP_DBFLAG_GLOBAL_OVERLAY;
1388                 }
1389
1390                 /* Save a pointer to ourself in bi_private.
1391                  */
1392                 oi->oi_bi.bi_private = oi;
1393                 oi->oi_list = NULL;
1394                 bi = (BackendInfo *)oi;
1395
1396                 bi->bi_type = (char *)overtype;
1397
1398                 bi->bi_db_config = over_db_config;
1399                 bi->bi_db_open = over_db_open;
1400                 bi->bi_db_close = over_db_close;
1401                 bi->bi_db_destroy = over_db_destroy;
1402
1403                 bi->bi_op_bind = over_op_bind;
1404                 bi->bi_op_unbind = over_op_unbind;
1405                 bi->bi_op_search = over_op_search;
1406                 bi->bi_op_compare = over_op_compare;
1407                 bi->bi_op_modify = over_op_modify;
1408                 bi->bi_op_modrdn = over_op_modrdn;
1409                 bi->bi_op_add = over_op_add;
1410                 bi->bi_op_delete = over_op_delete;
1411                 bi->bi_op_abandon = over_op_abandon;
1412                 bi->bi_op_cancel = over_op_cancel;
1413
1414                 bi->bi_extended = over_op_extended;
1415
1416                 /*
1417                  * this is fine because it has the same
1418                  * args of the operations; we need to rework
1419                  * all the hooks to share the same args
1420                  * of the operations...
1421                  */
1422                 bi->bi_operational = over_aux_operational;
1423                 bi->bi_chk_referrals = over_aux_chk_referrals;
1424                 bi->bi_chk_controls = over_aux_chk_controls;
1425
1426                 /* these have specific arglists */
1427                 bi->bi_entry_get_rw = over_entry_get_rw;
1428                 bi->bi_entry_release_rw = over_entry_release_rw;
1429                 bi->bi_access_allowed = over_access_allowed;
1430                 bi->bi_acl_group = over_acl_group;
1431                 bi->bi_acl_attribute = over_acl_attribute;
1432
1433                 bi->bi_connection_init = over_connection_init;
1434                 bi->bi_connection_destroy = over_connection_destroy;
1435
1436                 be->bd_info = bi;
1437
1438         } else {
1439                 if ( overlay_is_inst( be, ov ) ) {
1440                         if ( SLAPO_SINGLE( be ) ) {
1441                                 Debug( LDAP_DEBUG_ANY, "overlay_config(): "
1442                                         "overlay \"%s\" already in list\n",
1443                                         ov, 0, 0 );
1444                                 return 1;
1445                         }
1446                 }
1447
1448                 oi = be->bd_info->bi_private;
1449         }
1450
1451         /* Insert new overlay into list. By default overlays are
1452          * added to head of list and executed in LIFO order.
1453          */
1454         on2 = ch_calloc( 1, sizeof(slap_overinst) );
1455         *on2 = *on;
1456         on2->on_info = oi;
1457
1458         prev = &oi->oi_list;
1459         /* Do we need to find the insertion point? */
1460         if ( idx >= 0 ) {
1461                 int i;
1462
1463                 /* count current overlays */
1464                 for ( i=0, on=oi->oi_list; on; on=on->on_next, i++ );
1465
1466                 /* are we just appending a new one? */
1467                 if ( idx >= i )
1468                         idx = -1;
1469         }
1470         overlay_insert( be, on2, &prev, idx );
1471
1472         /* Any initialization needed? */
1473         if ( on2->on_bi.bi_db_init ) {
1474                 int rc;
1475                 be->bd_info = (BackendInfo *)on2;
1476                 rc = on2->on_bi.bi_db_init( be, cr);
1477                 be->bd_info = (BackendInfo *)oi;
1478                 if ( rc ) {
1479                         *prev = on2->on_next;
1480                         ch_free( on2 );
1481                         on2 = NULL;
1482                         return rc;
1483                 }
1484         }
1485
1486         if ( res )
1487                 *res = &on2->on_bi;
1488
1489         return 0;
1490 }