text: /* refint.c - referential integrity module */
  /* $OpenLDAP$ */
  /* This work is part of OpenLDAP Software <http://www.openldap.org/>.
   *
   * Copyright 2004-2021 The OpenLDAP Foundation.
   * Portions Copyright 2004 Symas Corporation.
   * All rights reserved.
   *
   * Redistribution and use in source and binary forms, with or without
   * modification, are permitted only as authorized by the OpenLDAP
   * Public License.
   *
   * A copy of this license is available in the file LICENSE in the
   * top-level directory of the distribution or, alternatively, at
   * <http://www.OpenLDAP.org/license.html>.
   */
  /* ACKNOWLEDGEMENTS:
   * This work was initially developed by Symas Corp. for inclusion in
   * OpenLDAP Software.  This work was sponsored by Hewlett-Packard.
   */
  
  #include "portable.h"
  
  /* This module maintains referential integrity for a set of
   * DN-valued attributes by searching for all references to a given
   * DN whenever the DN is changed or its entry is deleted, and making
   * the appropriate update.
   *
   * Updates are performed using the database rootdn in a separate task
   * to allow the original operation to complete immediately.
   */
  
  #ifdef SLAPD_OVER_REFINT
  
  #include <stdio.h>
  
  #include <ac/string.h>
  #include <ac/socket.h>
  
  #include "slap.h"
  #include "slap-config.h"
  #include "ldap_rq.h"
  
  static slap_overinst refint;
  
  /* The DN to use in the ModifiersName for all refint updates */
  static BerValue refint_dn = BER_BVC("cn=Referential Integrity Overlay");
  static BerValue refint_ndn = BER_BVC("cn=referential integrity overlay");
  
  typedef struct refint_attrs_s {
  	struct refint_attrs_s	*next;
  	AttributeDescription	*attr;
  	BerVarray		old_vals;
  	BerVarray		old_nvals;
  	BerVarray		new_vals;
  	BerVarray		new_nvals;
  	int				ra_numvals;
  	int				dont_empty;
  } refint_attrs;
  
  typedef struct dependents_s {
  	struct dependents_s *next;
  	BerValue dn;				/* target dn */
  	BerValue ndn;
  	refint_attrs *attrs;
  } dependent_data;
  
  typedef struct refint_q {
  	struct refint_q *next;
  	struct refint_data_s *rdata;
  	dependent_data *attrs;		/* entries and attrs returned from callback */
  	BackendDB *db;
  	BerValue olddn;
  	BerValue oldndn;
  	BerValue newdn;
  	BerValue newndn;
  	int do_sub;
  } refint_q;
  
  typedef struct refint_data_s {
  	struct refint_attrs_s *attrs;	/* list of known attrs */
  	BerValue dn;				/* basedn in parent, */
  	BerValue nothing;			/* the nothing value, if needed */
  	BerValue nnothing;			/* normalized nothingness */
  	BerValue refint_dn;			/* modifier's name */
  	BerValue refint_ndn;			/* normalized modifier's name */
  	struct re_s *qtask;
  	refint_q *qhead;
  	refint_q *qtail;
  	BackendDB *db;
  	ldap_pvt_thread_mutex_t qmutex;
  } refint_data;
  
  typedef struct refint_pre_s {
  	slap_overinst *on;
  	int do_sub;
  } refint_pre;
  
  #define	RUNQ_INTERVAL	36000	/* a long time */
  
  static MatchingRule	*mr_dnSubtreeMatch;
  
  enum {
  	REFINT_ATTRS = 1,
  	REFINT_NOTHING,
  	REFINT_MODIFIERSNAME
  };
  
  static ConfigDriver refint_cf_gen;
  
  static ConfigTable refintcfg[] = {
  	{ "refint_attributes", "attribute...", 2, 0, 0,
  	  ARG_MAGIC|REFINT_ATTRS, refint_cf_gen,
  	  "( OLcfgOvAt:11.1 NAME 'olcRefintAttribute' "
  	  "DESC 'Attributes for referential integrity' "
  	  "EQUALITY caseIgnoreMatch "
  	  "SYNTAX OMsDirectoryString )", NULL, NULL },
  	{ "refint_nothing", "string", 2, 2, 0,
  	  ARG_DN|ARG_QUOTE|ARG_MAGIC|REFINT_NOTHING, refint_cf_gen,
  	  "( OLcfgOvAt:11.2 NAME 'olcRefintNothing' "
  	  "DESC 'Replacement DN to supply when needed' "
  	  "EQUALITY distinguishedNameMatch "
  	  "SYNTAX OMsDN SINGLE-VALUE )", NULL, NULL },
  	{ "refint_modifiersName", "DN", 2, 2, 0,
  	  ARG_DN|ARG_QUOTE|ARG_MAGIC|REFINT_MODIFIERSNAME, refint_cf_gen,
  	  "( OLcfgOvAt:11.3 NAME 'olcRefintModifiersName' "
  	  "DESC 'The DN to use as modifiersName' "
  	  "EQUALITY distinguishedNameMatch "
  	  "SYNTAX OMsDN SINGLE-VALUE )", NULL, NULL },
  	{ NULL, NULL, 0, 0, 0, ARG_IGNORED }
  };
  
  static ConfigOCs refintocs[] = {
  	{ "( OLcfgOvOc:11.1 "
  	  "NAME 'olcRefintConfig' "
  	  "DESC 'Referential integrity configuration' "
  	  "SUP olcOverlayConfig "
  	  "MAY ( olcRefintAttribute "
  		"$ olcRefintNothing "
  		"$ olcRefintModifiersName "
  	  ") )",
  	  Cft_Overlay, refintcfg },
  	{ NULL, 0, NULL }
  };
  
  static int
  refint_cf_gen(ConfigArgs *c)
  {
  	slap_overinst *on = (slap_overinst *)c->bi;
  	refint_data *dd = (refint_data *)on->on_bi.bi_private;
  	refint_attrs *ip, *pip, **pipp = NULL;
  	AttributeDescription *ad;
  	const char *text;
  	int rc = ARG_BAD_CONF;
  	int i;
  
  	switch ( c->op ) {
  	case SLAP_CONFIG_EMIT:
  		switch ( c->type ) {
  		case REFINT_ATTRS:
  			ip = dd->attrs;
  			while ( ip ) {
  				value_add_one( &c->rvalue_vals,
  					       &ip->attr->ad_cname );
  				ip = ip->next;
  			}
  			rc = 0;
  			break;
  		case REFINT_NOTHING:
  			if ( !BER_BVISEMPTY( &dd->nothing )) {
  				rc = value_add_one( &c->rvalue_vals,
  						    &dd->nothing );
  				if ( rc ) return rc;
  				rc = value_add_one( &c->rvalue_nvals,
  						    &dd->nnothing );
  				return rc;
  			}
  			rc = 0;
  			break;
  		case REFINT_MODIFIERSNAME:
  			if ( !BER_BVISEMPTY( &dd->refint_dn )) {
  				rc = value_add_one( &c->rvalue_vals,
  						    &dd->refint_dn );
  				if ( rc ) return rc;
  				rc = value_add_one( &c->rvalue_nvals,
  						    &dd->refint_ndn );
  				return rc;
  			}
  			rc = 0;
  			break;
  		default:
  			abort ();
  		}
  		break;
  	case LDAP_MOD_DELETE:
  		switch ( c->type ) {
  		case REFINT_ATTRS:
  			pipp = &dd->attrs;
  			if ( c->valx < 0 ) {
  				ip = *pipp;
  				*pipp = NULL;
  				while ( ip ) {
  					pip = ip;
  					ip = ip->next;
  					ch_free ( pip );
  				}
  			} else {
  				/* delete from linked list */
  				for ( i=0; i < c->valx; ++i ) {
  					pipp = &(*pipp)->next;
  				}
  				ip = *pipp;
  				*pipp = (*pipp)->next;
  
  				/* AttributeDescriptions are global so
  				 * shouldn't be freed here... */
  				ch_free ( ip );
  			}
  			rc = 0;
  			break;
  		case REFINT_NOTHING:
  			ch_free( dd->nothing.bv_val );
  			ch_free( dd->nnothing.bv_val );
  			BER_BVZERO( &dd->nothing );
  			BER_BVZERO( &dd->nnothing );
  			rc = 0;
  			break;
  		case REFINT_MODIFIERSNAME:
  			ch_free( dd->refint_dn.bv_val );
  			ch_free( dd->refint_ndn.bv_val );
  			BER_BVZERO( &dd->refint_dn );
  			BER_BVZERO( &dd->refint_ndn );
  			rc = 0;
  			break;
  		default:
  			abort ();
  		}
  		break;
  	case SLAP_CONFIG_ADD:
  		/* fallthru to LDAP_MOD_ADD */
  	case LDAP_MOD_ADD:
  		switch ( c->type ) {
  		case REFINT_ATTRS:
  			rc = 0;
  			for ( i=1; i < c->argc; ++i ) {
  				ad = NULL;
  				if ( slap_str2ad ( c->argv[i], &ad, &text )
  				     == LDAP_SUCCESS) {
  					ip = ch_malloc (
  						sizeof ( refint_attrs ) );
  					ip->attr = ad;
  					ip->next = dd->attrs;
  					dd->attrs = ip;
  				} else {
  					snprintf( c->cr_msg, sizeof( c->cr_msg ),
  						"%s <%s>: %s", c->argv[0], c->argv[i], text );
  					Debug ( LDAP_DEBUG_CONFIG|LDAP_DEBUG_NONE,
  						"%s: %s\n", c->log, c->cr_msg );
  					rc = ARG_BAD_CONF;
  				}
  			}
  			break;
  		case REFINT_NOTHING:
  			if ( !BER_BVISNULL( &c->value_ndn )) {
  				ch_free ( dd->nothing.bv_val );
  				ch_free ( dd->nnothing.bv_val );
  				dd->nothing = c->value_dn;
  				dd->nnothing = c->value_ndn;
  				rc = 0;
  			} else {
  				rc = ARG_BAD_CONF;
  			}
  			break;
  		case REFINT_MODIFIERSNAME:
  			if ( !BER_BVISNULL( &c->value_ndn )) {
  				ch_free( dd->refint_dn.bv_val );
  				ch_free( dd->refint_ndn.bv_val );
  				dd->refint_dn = c->value_dn;
  				dd->refint_ndn = c->value_ndn;
  				rc = 0;
  			} else {
  				rc = ARG_BAD_CONF;
  			}
  			break;
  		default:
  			abort ();
  		}
  		break;
  	default:
  		abort ();
  	}
  
  	return rc;
  }
  
  /*
  ** allocate new refint_data;
  ** store in on_bi.bi_private;
  **
  */
  
  static int
  refint_db_init(
  	BackendDB	*be,
  	ConfigReply	*cr
  )
  {
  	slap_overinst *on = (slap_overinst *)be->bd_info;
  	refint_data *id = ch_calloc(1,sizeof(refint_data));
  
  	on->on_bi.bi_private = id;
  	ldap_pvt_thread_mutex_init( &id->qmutex );
  	return(0);
  }
  
  static int
  refint_db_destroy(
  	BackendDB	*be,
  	ConfigReply	*cr
  )
  {
  	slap_overinst *on = (slap_overinst *)be->bd_info;
  
  	if ( on->on_bi.bi_private ) {
  		refint_data *id = on->on_bi.bi_private;
  		refint_attrs *ii, *ij;
  
  		on->on_bi.bi_private = NULL;
  		ldap_pvt_thread_mutex_destroy( &id->qmutex );
  
  		for(ii = id->attrs; ii; ii = ij) {
  			ij = ii->next;
  			ch_free(ii);
  		}
  
  		ch_free( id->nothing.bv_val );
  		BER_BVZERO( &id->nothing );
  		ch_free( id->nnothing.bv_val );
  		BER_BVZERO( &id->nnothing );
  
  		ch_free( id );
  	}
  	return(0);
  }
  
  /*
  ** initialize, copy basedn if not already set
  **
  */
  
  static int
  refint_open(
  	BackendDB *be,
  	ConfigReply *cr
  )
  {
  	slap_overinst *on	= (slap_overinst *)be->bd_info;
  	refint_data *id	= on->on_bi.bi_private;
  
  	if ( BER_BVISNULL( &id->dn )) {
  		if ( BER_BVISNULL( &be->be_nsuffix[0] ))
  			return -1;
  		ber_dupbv( &id->dn, &be->be_nsuffix[0] );
  	}
  	if ( BER_BVISNULL( &id->refint_dn ) ) {
  		ber_dupbv( &id->refint_dn, &refint_dn );
  		ber_dupbv( &id->refint_ndn, &refint_ndn );
  	}
  
  	/*
  	** find the backend that matches our configured basedn;
  	** make sure it exists and has search and modify methods;
  	**
  	*/
  
  	if ( on->on_info->oi_origdb != frontendDB ) {
  		BackendDB *db = select_backend(&id->dn, 1);
  
  		if ( db ) {
  			BackendInfo *bi;
  			if ( db == be )
  				bi = on->on_info->oi_orig;
  			else
  				bi = db->bd_info;
  			if ( !bi->bi_op_search || !bi->bi_op_modify ) {
  				Debug( LDAP_DEBUG_CONFIG,
  					"refint_response: backend missing search and/or modify\n" );
  				return -1;
  			}
  			id->db = db;
  		} else {
  			Debug( LDAP_DEBUG_CONFIG,
  				"refint_response: no backend for our baseDN %s??\n",
  				id->dn.bv_val );
  			return -1;
  		}
  	}
  	return(0);
  }
  
  
  /*
  ** free our basedn;
  ** free our refintdn
  **
  */
  
  static int
  refint_close(
  	BackendDB *be,
  	ConfigReply *cr
  )
  {
  	slap_overinst *on	= (slap_overinst *) be->bd_info;
  	refint_data *id	= on->on_bi.bi_private;
  
  	ch_free( id->dn.bv_val );
  	BER_BVZERO( &id->dn );
  	ch_free( id->refint_dn.bv_val );
  	BER_BVZERO( &id->refint_dn );
  	ch_free( id->refint_ndn.bv_val );
  	BER_BVZERO( &id->refint_ndn );
  
  	return(0);
  }
  
  /*
  ** search callback
  ** generates a list of Attributes from search results
  */
  
  static int
  refint_search_cb(
  	Operation *op,
  	SlapReply *rs
  )
  {
  	Attribute *a;
  	BerVarray b = NULL;
  	refint_q *rq = op->o_callback->sc_private;
  	refint_data *dd = rq->rdata;
  	refint_attrs *ia, *da = dd->attrs, *na;
  	dependent_data *ip;
  	int i;
  
  	Debug(LDAP_DEBUG_TRACE, "refint_search_cb <%s>\n",
  		rs->sr_entry ? rs->sr_entry->e_name.bv_val : "NOTHING" );
  
  	if (rs->sr_type != REP_SEARCH || !rs->sr_entry) return(0);
  
  	/*
  	** foreach configured attribute type:
  	**	if this attr exists in the search result,
  	**	and it has a value matching the target:
  	**		allocate an attr;
  	**		save/build DNs of any subordinate matches;
  	**		handle special case: found exact + subordinate match;
  	**		handle olcRefintNothing;
  	**
  	*/
  
  	ip = op->o_tmpalloc(sizeof(dependent_data), op->o_tmpmemctx );
  	ber_dupbv_x( &ip->dn, &rs->sr_entry->e_name, op->o_tmpmemctx );
  	ber_dupbv_x( &ip->ndn, &rs->sr_entry->e_nname, op->o_tmpmemctx );
  	ip->next = rq->attrs;
  	rq->attrs = ip;
  	ip->attrs = NULL;
  	for(ia = da; ia; ia = ia->next) {
  		if ( (a = attr_find(rs->sr_entry->e_attrs, ia->attr) ) ) {
  			int exact = -1, is_exact;
  
  			na = NULL;
  
  			/* Are we doing subtree matching or simple equality? */
  			if ( rq->do_sub ) {
  			for(i = 0, b = a->a_nvals; b[i].bv_val; i++) {
  				if(dnIsSuffix(&b[i], &rq->oldndn)) {
  					is_exact = b[i].bv_len == rq->oldndn.bv_len;
  
  					/* Paranoia: skip buggy duplicate exact match,
  					 * it would break ra_numvals
  					 */
  					if ( is_exact && exact >= 0 )
  						continue;
  
  					/* first match? create structure */
  					if ( na == NULL ) {
  						na = op->o_tmpcalloc( 1,
  							sizeof( refint_attrs ),
  							op->o_tmpmemctx );
  						na->next = ip->attrs;
  						ip->attrs = na;
  						na->attr = ia->attr;
  					}
  
  					na->ra_numvals++;
  
  					if ( is_exact ) {
  						/* Exact match: refint_repair will deduce the DNs */
  						exact = i;
  
  					} else {
  						/* Subordinate match */
  						struct berval	newsub, newdn, olddn, oldndn;
  
  						/* Save old DN */
  						ber_dupbv_x( &olddn, &a->a_vals[i], op->o_tmpmemctx );
  						ber_bvarray_add_x( &na->old_vals, &olddn, op->o_tmpmemctx );
  
  						ber_dupbv_x( &oldndn, &a->a_nvals[i], op->o_tmpmemctx );
  						ber_bvarray_add_x( &na->old_nvals, &oldndn, op->o_tmpmemctx );
  
  						if ( BER_BVISEMPTY( &rq->newdn ) )
  							continue;
  
  						/* Rename subordinate match: Build new DN */
  						newsub = a->a_vals[i];
  						newsub.bv_len -= rq->olddn.bv_len + 1;
  						build_new_dn( &newdn, &rq->newdn, &newsub, op->o_tmpmemctx );
  						ber_bvarray_add_x( &na->new_vals, &newdn, op->o_tmpmemctx );
  
  						newsub = a->a_nvals[i];
  						newsub.bv_len -= rq->oldndn.bv_len + 1;
  						build_new_dn( &newdn, &rq->newndn, &newsub, op->o_tmpmemctx );
  						ber_bvarray_add_x( &na->new_nvals, &newdn, op->o_tmpmemctx );
  					}
  				}
  			}
  
  			/* If we got both subordinate and exact match,
  			 * refint_repair won't special-case the exact match */
  			if ( exact >= 0 && na->old_vals ) {
  				struct berval	dn;
  
  				ber_dupbv_x( &dn, &a->a_vals[exact], op->o_tmpmemctx );
  				ber_bvarray_add_x( &na->old_vals, &dn, op->o_tmpmemctx );
  				ber_dupbv_x( &dn, &a->a_nvals[exact], op->o_tmpmemctx );
  				ber_bvarray_add_x( &na->old_nvals, &dn, op->o_tmpmemctx );
  
  				if ( !BER_BVISEMPTY( &rq->newdn ) ) {
  					ber_dupbv_x( &dn, &rq->newdn, op->o_tmpmemctx );
  					ber_bvarray_add_x( &na->new_vals, &dn, op->o_tmpmemctx );
  					ber_dupbv_x( &dn, &rq->newndn, op->o_tmpmemctx );
  					ber_bvarray_add_x( &na->new_nvals, &dn, op->o_tmpmemctx );
  				}
  			}
  			} else {
  				/* entry has no children, just equality matching */
  				is_exact = attr_valfind( a,
  					SLAP_MR_EQUALITY|SLAP_MR_ASSERTED_VALUE_NORMALIZED_MATCH|
  					SLAP_MR_ATTRIBUTE_VALUE_NORMALIZED_MATCH, &rq->oldndn, &i, NULL );
  				if ( is_exact == LDAP_SUCCESS ) {
  					na = op->o_tmpcalloc( 1,
  						sizeof( refint_attrs ),
  						op->o_tmpmemctx );
  					na->next = ip->attrs;
  					ip->attrs = na;
  					na->attr = ia->attr;
  					na->ra_numvals = 1;
  				}
  			}
  
  			/* Deleting/replacing all values and a nothing DN is configured? */
  			if ( na && na->ra_numvals == a->a_numvals && !BER_BVISNULL(&dd->nothing) )
  				na->dont_empty = 1;
  
  			Debug( LDAP_DEBUG_TRACE, "refint_search_cb: %s: %s (#%d)\n",
  				a->a_desc->ad_cname.bv_val, rq->olddn.bv_val, i );
  		}
  	}
  
  	return(0);
  }
  
  static int
  refint_repair(
  	Operation	*op,
  	refint_data	*id,
  	refint_q	*rq )
  {
  	dependent_data	*dp;
  	SlapReply		rs = {REP_RESULT};
  	Operation		op2;
  	unsigned long	opid;
  	int		rc;
  	int	cache;
  
  	op->o_callback->sc_response = refint_search_cb;
  	op->o_req_dn = op->o_bd->be_suffix[ 0 ];
  	op->o_req_ndn = op->o_bd->be_nsuffix[ 0 ];
  	op->o_dn = op->o_bd->be_rootdn;
  	op->o_ndn = op->o_bd->be_rootndn;
  	cache = op->o_do_not_cache;
  	op->o_do_not_cache = 1;
  
  	/* search */
  	rc = op->o_bd->be_search( op, &rs );
  	op->o_do_not_cache = cache;
  
  	if ( rc != LDAP_SUCCESS ) {
  		Debug( LDAP_DEBUG_TRACE,
  			"refint_repair: search failed: %d\n",
  			rc );
  		return rc;
  	}
  
  	/* safety? paranoid just in case */
  	if ( op->o_callback->sc_private == NULL ) {
  		Debug( LDAP_DEBUG_TRACE,
  			"refint_repair: callback wiped out sc_private?!\n" );
  		return 0;
  	}
  
  	/* Set up the Modify requests */
  	op->o_callback->sc_response = &slap_null_cb;
  
  	/*
  	 * [our search callback builds a list of attrs]
  	 * foreach attr:
  	 *	make sure its dn has a backend;
  	 *	build Modification* chain;
  	 *	call the backend modify function;
  	 *
  	 */
  
  	opid = op->o_opid;
  	op2 = *op;
  	for ( dp = rq->attrs; dp; dp = dp->next ) {
  		SlapReply	rs2 = {REP_RESULT};
  		refint_attrs	*ra;
  		Modifications	*m;
  
  		if ( dp->attrs == NULL ) continue; /* TODO: Is this needed? */
  
  		op2.o_bd = select_backend( &dp->ndn, 1 );
  		if ( !op2.o_bd ) {
  			Debug( LDAP_DEBUG_TRACE,
  				"refint_repair: no backend for DN %s!\n",
  				dp->dn.bv_val );
  			continue;
  		}
  		op2.o_tag = LDAP_REQ_MODIFY;
  		op2.orm_modlist = NULL;
  		op2.o_req_dn	= dp->dn;
  		op2.o_req_ndn	= dp->ndn;
  		/* Internal ops, never replicate these */
  		op2.orm_no_opattrs = 1;
  		op2.o_dont_replicate = 1;
  		op2.o_opid = 0;
  
  		/* Set our ModifiersName */
  		if ( SLAP_LASTMOD( op->o_bd ) ) {
  				m = op2.o_tmpalloc( sizeof(Modifications) +
  					4*sizeof(BerValue), op2.o_tmpmemctx );
  				m->sml_next = op2.orm_modlist;
  				op2.orm_modlist = m;
  				m->sml_op = LDAP_MOD_REPLACE;
  				m->sml_flags = SLAP_MOD_INTERNAL;
  				m->sml_desc = slap_schema.si_ad_modifiersName;
  				m->sml_type = m->sml_desc->ad_cname;
  				m->sml_numvals = 1;
  				m->sml_values = (BerVarray)(m+1);
  				m->sml_nvalues = m->sml_values+2;
  				BER_BVZERO( &m->sml_values[1] );
  				BER_BVZERO( &m->sml_nvalues[1] );
  				m->sml_values[0] = id->refint_dn;
  				m->sml_nvalues[0] = id->refint_ndn;
  		}
  
  		for ( ra = dp->attrs; ra; ra = ra->next ) {
  			size_t	len;
  
  			/* Add values */
  			if ( ra->dont_empty || !BER_BVISEMPTY( &rq->newdn ) ) {
  				len = sizeof(Modifications);
  
  				if ( ra->new_vals == NULL ) {
  					len += 4*sizeof(BerValue);
  				}
  
  				m = op2.o_tmpalloc( len, op2.o_tmpmemctx );
  				m->sml_next = op2.orm_modlist;
  				op2.orm_modlist = m;
  				m->sml_op = LDAP_MOD_ADD;
  				m->sml_flags = 0;
  				m->sml_desc = ra->attr;
  				m->sml_type = ra->attr->ad_cname;
  				if ( ra->new_vals == NULL ) {
  					m->sml_values = (BerVarray)(m+1);
  					m->sml_nvalues = m->sml_values+2;
  					BER_BVZERO( &m->sml_values[1] );
  					BER_BVZERO( &m->sml_nvalues[1] );
  					m->sml_numvals = 1;
  					if ( BER_BVISEMPTY( &rq->newdn ) ) {
  						m->sml_values[0] = id->nothing;
  						m->sml_nvalues[0] = id->nnothing;
  					} else {
  						m->sml_values[0] = rq->newdn;
  						m->sml_nvalues[0] = rq->newndn;
  					}
  				} else {
  					m->sml_values = ra->new_vals;
  					m->sml_nvalues = ra->new_nvals;
  					m->sml_numvals = ra->ra_numvals;
  				}
  			}
  
  			/* Delete values */
  			len = sizeof(Modifications);
  			if ( ra->old_vals == NULL ) {
  				len += 4*sizeof(BerValue);
  			}
  			m = op2.o_tmpalloc( len, op2.o_tmpmemctx );
  			m->sml_next = op2.orm_modlist;
  			op2.orm_modlist = m;
  			m->sml_op = LDAP_MOD_DELETE;
  			m->sml_flags = 0;
  			m->sml_desc = ra->attr;
  			m->sml_type = ra->attr->ad_cname;
  			if ( ra->old_vals == NULL ) {
  				m->sml_numvals = 1;
  				m->sml_values = (BerVarray)(m+1);
  				m->sml_nvalues = m->sml_values+2;
  				m->sml_values[0] = rq->olddn;
  				m->sml_nvalues[0] = rq->oldndn;
  				BER_BVZERO( &m->sml_values[1] );
  				BER_BVZERO( &m->sml_nvalues[1] );
  			} else {
  				m->sml_values = ra->old_vals;
  				m->sml_nvalues = ra->old_nvals;
  				m->sml_numvals = ra->ra_numvals;
  			}
  		}
  
  		op2.o_dn = op2.o_bd->be_rootdn;
  		op2.o_ndn = op2.o_bd->be_rootndn;
  		rc = op2.o_bd->be_modify( &op2, &rs2 );
  		if ( rc != LDAP_SUCCESS ) {
  			Debug( LDAP_DEBUG_TRACE,
  				"refint_repair: dependent modify failed: %d\n",
  				rs2.sr_err );
  		}
  
  		while ( ( m = op2.orm_modlist ) ) {
  			op2.orm_modlist = m->sml_next;
  			op2.o_tmpfree( m, op2.o_tmpmemctx );
  		}
  	}
  	op2.o_opid = opid;
  
  	return 0;
  }
  
  static void *
  refint_qtask( void *ctx, void *arg )
  {
  	struct re_s *rtask = arg;
  	refint_data *id = rtask->arg;
  	Connection conn = {0};
  	OperationBuffer opbuf;
  	Operation *op;
  	slap_callback cb = { NULL, NULL, NULL, NULL };
  	Filter ftop, *fptr;
  	refint_q *rq;
  	refint_attrs *ip;
  	int pausing = 0, rc = 0;
  
  	connection_fake_init( &conn, &opbuf, ctx );
  	op = &opbuf.ob_op;
  
  	/*
  	** build a search filter for all configured attributes;
  	** populate our Operation;
  	** pass our data (attr list, dn) to backend via sc_private;
  	** call the backend search function;
  	** nb: (|(one=thing)) is valid, but do smart formatting anyway;
  	** nb: 16 is arbitrarily a dozen or so extra bytes;
  	**
  	*/
  
  	ftop.f_choice = LDAP_FILTER_OR;
  	ftop.f_next = NULL;
  	ftop.f_or = NULL;
  	op->ors_filter = &ftop;
  	for(ip = id->attrs; ip; ip = ip->next) {
  		/* this filter can be either EQUALITY or EXT */
  		fptr = op->o_tmpcalloc( sizeof(Filter) + sizeof(MatchingRuleAssertion),
  			1, op->o_tmpmemctx );
  		fptr->f_mra = (MatchingRuleAssertion *)(fptr+1);
  		fptr->f_mr_rule = mr_dnSubtreeMatch;
  		fptr->f_mr_rule_text = mr_dnSubtreeMatch->smr_bvoid;
  		fptr->f_mr_desc = ip->attr;
  		fptr->f_mr_dnattrs = 0;
  		fptr->f_next = ftop.f_or;
  		ftop.f_or = fptr;
  	}
  
  	for (;;) {
  		dependent_data	*dp, *dp_next;
  		refint_attrs *ra, *ra_next;
  
  		if ( ldap_pvt_thread_pool_pausing( &connection_pool ) > 0 ) {
  			pausing = 1;
  			break;
  		}
  
  		/* Dequeue an op */
  		ldap_pvt_thread_mutex_lock( &id->qmutex );
  		rq = id->qhead;
  		if ( rq ) {
  			id->qhead = rq->next;
  			if ( !id->qhead )
  				id->qtail = NULL;
  		}
  		ldap_pvt_thread_mutex_unlock( &id->qmutex );
  		if ( !rq )
  			break;
  
  		for (fptr = ftop.f_or; fptr; fptr = fptr->f_next ) {
  			fptr->f_mr_value = rq->oldndn;
  			/* Use (attr:dnSubtreeMatch:=value) to catch subtree rename
  			 * and subtree delete where supported */
  			if (rq->do_sub)
  				fptr->f_choice = LDAP_FILTER_EXT;
  			else
  				fptr->f_choice = LDAP_FILTER_EQUALITY;
  		}
  
  		filter2bv_x( op, op->ors_filter, &op->ors_filterstr );
  
  		/* callback gets the searched dn instead */
  		cb.sc_private	= rq;
  		cb.sc_response	= refint_search_cb;
  		op->o_callback	= &cb;
  		op->o_tag	= LDAP_REQ_SEARCH;
  		op->ors_scope	= LDAP_SCOPE_SUBTREE;
  		op->ors_deref	= LDAP_DEREF_NEVER;
  		op->ors_limit   = NULL;
  		op->ors_slimit	= SLAP_NO_LIMIT;
  		op->ors_tlimit	= SLAP_NO_LIMIT;
  
  		/* no attrs! */
  		op->ors_attrs = slap_anlist_no_attrs;
  
  		slap_op_time( &op->o_time, &op->o_tincr );
  
  		if ( rq->db != NULL ) {
  			op->o_bd = rq->db;
  			rc = refint_repair( op, id, rq );
  
  		} else {
  			BackendDB	*be;
  
  			LDAP_STAILQ_FOREACH( be, &backendDB, be_next ) {
  				/* we may want to skip cn=config */
  				if ( be == LDAP_STAILQ_FIRST(&backendDB) ) {
  					continue;
  				}
  
  				if ( be->be_search && be->be_modify ) {
  					op->o_bd = be;
  					rc = refint_repair( op, id, rq );
  				}
  			}
  		}
  
  		for ( dp = rq->attrs; dp; dp = dp_next ) {
  			dp_next = dp->next;
  			for ( ra = dp->attrs; ra; ra = ra_next ) {
  				ra_next = ra->next;
  				ber_bvarray_free_x( ra->new_nvals, op->o_tmpmemctx );
  				ber_bvarray_free_x( ra->new_vals, op->o_tmpmemctx );
  				ber_bvarray_free_x( ra->old_nvals, op->o_tmpmemctx );
  				ber_bvarray_free_x( ra->old_vals, op->o_tmpmemctx );
  				op->o_tmpfree( ra, op->o_tmpmemctx );
  			}
  			op->o_tmpfree( dp->ndn.bv_val, op->o_tmpmemctx );
  			op->o_tmpfree( dp->dn.bv_val, op->o_tmpmemctx );
  			op->o_tmpfree( dp, op->o_tmpmemctx );
  		}
  		op->o_tmpfree( op->ors_filterstr.bv_val, op->o_tmpmemctx );
  		if ( rc == LDAP_BUSY ) {
  			pausing = 1;
  			/* re-queue this op */
  			ldap_pvt_thread_mutex_lock( &id->qmutex );
  			rq->next = id->qhead;
  			id->qhead = rq;
  			if ( !id->qtail )
  				id->qtail = rq;
  			ldap_pvt_thread_mutex_unlock( &id->qmutex );
  			break;
  		}
  
  		if ( !BER_BVISNULL( &rq->newndn )) {
  			ch_free( rq->newndn.bv_val );
  			ch_free( rq->newdn.bv_val );
  		}
  		ch_free( rq->oldndn.bv_val );
  		ch_free( rq->olddn.bv_val );
  		ch_free( rq );
  	}
  
  	/* free filter */
  	for ( fptr = ftop.f_or; fptr; ) {
  		Filter *f_next = fptr->f_next;
  		op->o_tmpfree( fptr, op->o_tmpmemctx );
  		fptr = f_next;
  	}
  
  	/* wait until we get explicitly scheduled again */
  	ldap_pvt_thread_mutex_lock( &slapd_rq.rq_mutex );
  	ldap_pvt_runqueue_stoptask( &slapd_rq, id->qtask );
  	if ( pausing ) {
  		/* try to run again as soon as the pause is done */
  		id->qtask->interval.tv_sec = 0;
  		ldap_pvt_runqueue_resched( &slapd_rq, id->qtask, 0 );
  		id->qtask->interval.tv_sec = RUNQ_INTERVAL;
  	} else {
  		ldap_pvt_runqueue_resched( &slapd_rq,id->qtask, 1 );
  	}
  	ldap_pvt_thread_mutex_unlock( &slapd_rq.rq_mutex );
  
  	return NULL;
  }
  
  /*
  ** refint_response
  ** search for matching records and modify them
  */
  
  static int
  refint_response(
  	Operation *op,
  	SlapReply *rs
  )
  {
  	refint_pre *rp;
  	slap_overinst *on;
  	refint_data *id;
  	refint_q *rq;
  	refint_attrs *ip;
  	int ac;
  
  	/* If the main op failed or is not a Delete or ModRdn, ignore it */
  	if (( op->o_tag != LDAP_REQ_DELETE && op->o_tag != LDAP_REQ_MODRDN ) ||
  		rs->sr_err != LDAP_SUCCESS )
  		return SLAP_CB_CONTINUE;
  
  	rp = op->o_callback->sc_private;
  	on = rp->on;
  	id = on->on_bi.bi_private;
  
  	rq = ch_calloc( 1, sizeof( refint_q ));
  	ber_dupbv( &rq->olddn, &op->o_req_dn );
  	ber_dupbv( &rq->oldndn, &op->o_req_ndn );
  	rq->db = id->db;
  	rq->rdata = id;
  	rq->do_sub = rp->do_sub;
  
  	if ( op->o_tag == LDAP_REQ_MODRDN ) {
  		ber_dupbv( &rq->newdn, &op->orr_newDN );
  		ber_dupbv( &rq->newndn, &op->orr_nnewDN );
  	}
  
  	ldap_pvt_thread_mutex_lock( &id->qmutex );
  	if ( id->qtail ) {
  		id->qtail->next = rq;
  	} else {
  		id->qhead = rq;
  	}
  	id->qtail = rq;
  	ldap_pvt_thread_mutex_unlock( &id->qmutex );
  
  	ac = 0;
  	ldap_pvt_thread_mutex_lock( &slapd_rq.rq_mutex );
  	if ( !id->qtask ) {
  		id->qtask = ldap_pvt_runqueue_insert( &slapd_rq, RUNQ_INTERVAL,
  			refint_qtask, id, "refint_qtask",
  			op->o_bd->be_suffix[0].bv_val );
  		ac = 1;
  	} else {
  		if ( !ldap_pvt_runqueue_isrunning( &slapd_rq, id->qtask ) &&
  			!id->qtask->next_sched.tv_sec ) {
  			id->qtask->interval.tv_sec = 0;
  			ldap_pvt_runqueue_resched( &slapd_rq, id->qtask, 0 );
  			id->qtask->interval.tv_sec = RUNQ_INTERVAL;
  			ac = 1;
  		}
  	}
  	ldap_pvt_thread_mutex_unlock( &slapd_rq.rq_mutex );
  	if ( ac )
  		slap_wake_listener();
  
  	return SLAP_CB_CONTINUE;
  }
  
  /* Check if the target entry exists and has children.
   * Do nothing if target doesn't exist.
   */
  static int
  refint_preop(
  	Operation *op,
  	SlapReply *rs
  )
  {
  	slap_overinst *on = (slap_overinst *) op->o_bd->bd_info;
  	refint_data *id = on->on_bi.bi_private;
  	Entry *e;
  	int rc;
  
  	/* are any attrs configured? */
  	if ( !id->attrs )
  		return SLAP_CB_CONTINUE;
  
  	rc = overlay_entry_get_ov( op, &op->o_req_ndn, NULL, NULL, 0, &e, on );
  	if ( rc == LDAP_SUCCESS ) {
  		slap_callback *sc = op->o_tmpcalloc( 1,
  			sizeof(slap_callback)+sizeof(refint_pre), op->o_tmpmemctx );
  		refint_pre *rp = (refint_pre *)(sc+1);
  		rp->on = on;
  		rp->do_sub = 1;	/* assume there are children */
  		if ( op->o_bd->be_has_subordinates ) {
  			int has = 0;
  			rc = op->o_bd->be_has_subordinates( op, e, &has );
  			/* there definitely are not children */
  			if ( rc == LDAP_SUCCESS && has == LDAP_COMPARE_FALSE )
  				rp->do_sub = 0;
  		}
  		overlay_entry_release_ov( op, e, 0, on );
  		sc->sc_response = refint_response;
  		sc->sc_private = rp;
  		sc->sc_next = op->o_callback;
  		op->o_callback = sc;
  	}
  	return SLAP_CB_CONTINUE;
  }
  
  /*
  ** init_module is last so the symbols resolve "for free" --
  ** it expects to be called automagically during dynamic module initialization
  */
  
  int refint_initialize() {
  	int rc;
  
  	mr_dnSubtreeMatch = mr_find( "dnSubtreeMatch" );
  	if ( mr_dnSubtreeMatch == NULL ) {
  		Debug( LDAP_DEBUG_ANY, "refint_initialize: "
  			"unable to find MatchingRule 'dnSubtreeMatch'.\n" );
  		return 1;
  	}
  
  	/* statically declared just after the #includes at top */
  	refint.on_bi.bi_type = "refint";
  	refint.on_bi.bi_db_init = refint_db_init;
  	refint.on_bi.bi_db_destroy = refint_db_destroy;
  	refint.on_bi.bi_db_open = refint_open;
  	refint.on_bi.bi_db_close = refint_close;
  	refint.on_bi.bi_op_delete = refint_preop;
  	refint.on_bi.bi_op_modrdn = refint_preop;
  
  	refint.on_bi.bi_cf_ocs = refintocs;
  	rc = config_register_schema ( refintcfg, refintocs );
  	if ( rc ) return rc;
  
  	return(overlay_register(&refint));
  }
  
  #if SLAPD_OVER_REFINT == SLAPD_MOD_DYNAMIC && defined(PIC)
  int init_module(int argc, char *argv[]) {
  	return refint_initialize();
  }
  #endif
  
  #endif /* SLAPD_OVER_REFINT */
  